Interface MutableMapIterable<K,​V>

All Superinterfaces:
InternalIterable<V>, Iterable<V>, Map<K,​V>, MapIterable<K,​V>, RichIterable<V>
All Known Subinterfaces:
ConcurrentMutableMap<K,​V>, FixedSizeMap<K,​V>, MutableBiMap<K,​V>, MutableMap<K,​V>, MutableOrderedMap<K,​V>, MutableSortedMap<K,​V>
All Known Implementing Classes:
AbstractMutableMap, AbstractMutableMapIterable, AbstractMutableSortedMap, AbstractSynchronizedMapIterable, ConcurrentHashMap, ConcurrentHashMapUnsafe, ConcurrentMutableHashMap, HashBiMap, MapAdapter, OrderedMapAdapter, SortedMapAdapter, SynchronizedBiMap, SynchronizedMutableMap, SynchronizedSortedMap, TreeSortedMap, UnifiedMap, UnifiedMapWithHashingStrategy, UnmodifiableBiMap, UnmodifiableMutableMap, UnmodifiableMutableOrderedMap, UnmodifiableTreeMap

public interface MutableMapIterable<K,​V>
extends MapIterable<K,​V>, Map<K,​V>
Since:
6.0
  • Method Details

    • putPair

      default V putPair​(Pair<? extends K,​? extends V> keyValuePair)
      This method allows mutable map the ability to add an element in the form of Pair<? extends K, ? extends V>.
      Since:
      9.1.0
      See Also:
      Map.put(Object, Object)
    • add

      default V add​(Pair<? extends K,​? extends V> keyValuePair)
      This method allows mutable map the ability to add an element in the form of Pair<? extends K, ? extends V>.
      Returns:
      previous value in the map for the key, or null if no value exists for the key.
      See Also:
      Map.put(Object, Object)
    • removeKey

      V removeKey​(K key)
      Remove an entry from the map at the specified key.
      Returns:
      The value removed from entry at key, or null if not found.
      See Also:
      Map.remove(Object)
    • removeAllKeys

      default boolean removeAllKeys​(Set<? extends K> keys)
      Remove entries from the map at the specified keys.
      Returns:
      true if this map changed as a result of the call
      Since:
      10.0
    • removeIf

      default boolean removeIf​(Predicate2<? super K,​? super V> predicate)
      Remove an entry from the map if the predicate evaluates to true.
      Returns:
      true if any entry is removed.
      Since:
      10.0
    • getOrDefault

      default V getOrDefault​(Object key, V defaultValue)
      Specified by:
      getOrDefault in interface Map<K,​V>
      Specified by:
      getOrDefault in interface MapIterable<K,​V>
    • getIfAbsentPut

      V getIfAbsentPut​(K key, Function0<? extends V> function)
      Get and return the value in the Map at the specified key. Alternatively, if there is no value in the map at the key, return the result of evaluating the specified Function0, and put that value in the map at the specified key.
    • getIfAbsentPut

      V getIfAbsentPut​(K key, V value)
      Get and return the value in the Map at the specified key. Alternatively, if there is no value in the map at the key, return the specified value, and put that value in the map at the specified key.
      Since:
      5.0
    • getIfAbsentPutWithKey

      V getIfAbsentPutWithKey​(K key, Function<? super K,​? extends V> function)
      Get and return the value in the Map at the specified key. Alternatively, if there is no value in the map for that key return the result of evaluating the specified Function using the specified key, and put that value in the map at the specified key.
    • getIfAbsentPutWith

      <P> V getIfAbsentPutWith​(K key, Function<? super P,​? extends V> function, P parameter)
      Get and return the value in the Map at the specified key. Alternatively, if there is no value in the map for that key return the result of evaluating the specified Function using the specified parameter, and put that value in the map at the specified key.
    • updateValue

      V updateValue​(K key, Function0<? extends V> factory, Function<? super V,​? extends V> function)
      Looks up the value associated with key, applies the function to it, and replaces the value. If there is no value associated with key, starts it off with a value supplied by factory.
    • updateValueWith

      <P> V updateValueWith​(K key, Function0<? extends V> factory, Function2<? super V,​? super P,​? extends V> function, P parameter)
      Same as updateValue(Object, Function0, Function) with a Function2 and specified parameter which is passed to the function.
    • withKeyValue

      MutableMapIterable<K,​V> withKeyValue​(K key, V value)
      This method allows mutable, fixed size, and immutable maps the ability to add elements to their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original plus the additional key and value. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken:
       map = map.withKeyValue("new key", "new value");
       
      In the case of FixedSizeMap, a new instance will be returned by withKeyValue, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling put on themselves.
      See Also:
      Map.put(Object, Object)
    • withMap

      default MutableMapIterable<K,​V> withMap​(Map<? extends K,​? extends V> map)
      Similar to Map.putAll(Map), but returns this instead of void
      Since:
      10.3.0
      See Also:
      Map.putAll(Map)
    • withAllKeyValues

      MutableMapIterable<K,​V> withAllKeyValues​(Iterable<? extends Pair<? extends K,​? extends V>> keyValues)
      This method allows mutable, fixed size, and immutable maps the ability to add elements to their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original plus all of the additional keys and values. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken:
       map = map.withAllKeyValues(FastList.newListWith(PairImpl.of("new key", "new value")));
       
      In the case of FixedSizeMap, a new instance will be returned by withAllKeyValues, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling put on themselves.
      See Also:
      Map.put(Object, Object)
    • withAllKeyValueArguments

      MutableMapIterable<K,​V> withAllKeyValueArguments​(Pair<? extends K,​? extends V>... keyValuePairs)
      Convenience var-args version of withAllKeyValues
      See Also:
      withAllKeyValues(Iterable)
    • withoutKey

      MutableMapIterable<K,​V> withoutKey​(K key)
      This method allows mutable, fixed size, and immutable maps the ability to remove elements from their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original minus the key and value to be removed. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken:
       map = map.withoutKey("key");
       
      In the case of FixedSizeMap, a new instance will be returned by withoutKey, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling remove on themselves.
      See Also:
      Map.remove(Object)
    • withoutAllKeys

      MutableMapIterable<K,​V> withoutAllKeys​(Iterable<? extends K> keys)
      This method allows mutable, fixed size, and immutable maps the ability to remove elements from their existing elements. In order to support fixed size maps, a new instance of a map would have to be returned including the keys and values of the original minus all of the keys and values to be removed. In the case of mutable maps, the original map is modified and then returned. In order to use this method properly with mutable and fixed size maps the following approach must be taken:
       map = map.withoutAllKeys(FastList.newListWith("key1", "key2"));
       
      In the case of FixedSizeMap, a new instance will be returned by withoutAllKeys, and any variables that previously referenced the original map will need to be redirected to reference the new instance. In the case of a FastMap or UnifiedMap, you will be replacing the reference to map with map, since FastMap and UnifiedMap will both return "this" after calling remove on themselves.
      See Also:
      Map.remove(Object)
    • newEmpty

      MutableMapIterable<K,​V> newEmpty()
      Creates a new instance of the same type, using the default capacity and growth parameters.
    • asUnmodifiable

      MutableMapIterable<K,​V> asUnmodifiable()
      Returns an unmodifiable view of this map. This is the equivalent of using Collections.unmodifiableMap(this) only with a return type that supports the full iteration protocols available on MutableMapIterable. Methods which would mutate the underlying map will throw UnsupportedOperationExceptions.
      Returns:
      an unmodifiable view of this map.
      See Also:
      Collections.unmodifiableMap(Map)
    • asSynchronized

      MutableMapIterable<K,​V> asSynchronized()
      Returns a synchronized wrapper backed by this map. This is the equivalent of calling Collections.synchronizedMap(this) only with the more feature rich return type of MutableMapIterable.

      The preferred way of iterating over a synchronized map is to use the forEachKey(), forEachValue() and forEachKeyValue() methods which are properly synchronized internally.

        MutableMap synchedMap = map.asSynchronized();
      
        synchedMap.forEachKey(key -> ... );
        synchedMap.forEachValue(value -> ... );
        synchedMap.forEachKeyValue((key, value) -> ... );
       

      If you want to iterate imperatively over the keySet(), values(), or entrySet(), you will need to protect the iteration by wrapping the code in a synchronized block on the map.

      See Also:
      Collections.synchronizedMap(Map)
    • toImmutable

      ImmutableMapIterable<K,​V> toImmutable()
      Returns an immutable copy of this map. If the map is immutable, it returns itself.
      Specified by:
      toImmutable in interface MapIterable<K,​V>
    • tap

      MutableMapIterable<K,​V> tap​(Procedure<? super V> procedure)
      Description copied from interface: MapIterable
      Executes the Procedure for each value of the map and returns this.
       return peopleByCity.tap(person -> LOGGER.info(person.getName()));
       
      Specified by:
      tap in interface MapIterable<K,​V>
      Specified by:
      tap in interface RichIterable<K>
      See Also:
      RichIterable.forEach(Procedure)
    • flipUniqueValues

      MutableMapIterable<V,​K> flipUniqueValues()
      Description copied from interface: MapIterable
      Return the MapIterable that is obtained by flipping the direction of this map and making the associations from value to key.
           MapIterable<Integer, String> map = this.newMapWithKeysValues(1, "1", 2, "2", 3, "3");
           MapIterable<String, Integer> result = map.flipUniqueValues();
           Assert.assertTrue(result.equals(UnifiedMap.newWithKeysValues("1", 1, "2", 2, "3", 3)));
       
      Specified by:
      flipUniqueValues in interface MapIterable<K,​V>
    • flip

      MutableMultimap<V,​K> flip()
      Description copied from interface: MapIterable
      Given a map from Domain -> Range return a multimap from Range -> Domain. We chose the name 'flip' rather than 'invert' or 'transpose' since this method does not have the property of applying twice returns the original.

      Since the keys in the input are unique, the values in the output are unique, so the return type should be a SetMultimap. However since SetMultimap and SortedSetMultimap don't inherit from one another, SetMultimap here does not allow SortedMapIterable to have a SortedSetMultimap return. Thus we compromise and call this Multimap, even though all implementations will be a SetMultimap or SortedSetMultimap.

      Specified by:
      flip in interface MapIterable<K,​V>
    • select

      MutableMapIterable<K,​V> select​(Predicate2<? super K,​? super V> predicate)
      Description copied from interface: MapIterable
      For each key and value of the map the predicate is evaluated, if the result of the evaluation is true, that key and value are returned in a new map.
       MapIterable<City, Person> selected =
           peopleByCity.select((city, person) -> city.getName().equals("Anytown") && person.getLastName().equals("Smith"));
       
      Specified by:
      select in interface MapIterable<K,​V>
    • reject

      MutableMapIterable<K,​V> reject​(Predicate2<? super K,​? super V> predicate)
      Description copied from interface: MapIterable
      For each key and value of the map the predicate is evaluated, if the result of the evaluation is false, that key and value are returned in a new map.
       MapIterable<City, Person> rejected =
           peopleByCity.reject((city, person) -> city.getName().equals("Anytown") && person.getLastName().equals("Smith"));
       
      Specified by:
      reject in interface MapIterable<K,​V>
    • collect

      <K2,​ V2> MutableMapIterable<K2,​V2> collect​(Function2<? super K,​? super V,​Pair<K2,​V2>> function)
      Description copied from interface: MapIterable
      For each key and value of the map the function is evaluated. The results of these evaluations are returned in a new map. The map returned will use the values projected from the function rather than the original values.
       MapIterable<String, String> collected =
           peopleByCity.collect((City city, Person person) -> Pair.of(city.getCountry(), person.getAddress().getCity()));
       
      Specified by:
      collect in interface MapIterable<K,​V>
    • collectValues

      <R> MutableMapIterable<K,​R> collectValues​(Function2<? super K,​? super V,​? extends R> function)
      Description copied from interface: MapIterable
      For each key and value of the map the function is evaluated. The results of these evaluations are returned in a new map. The map returned will use the values projected from the function rather than the original values.
       MapIterable<City, String> collected =
           peopleByCity.collectValues((City city, Person person) -> person.getFirstName() + " " + person.getLastName());
       
      Specified by:
      collectValues in interface MapIterable<K,​V>
    • select

      MutableCollection<V> select​(Predicate<? super V> predicate)
      Description copied from interface: RichIterable
      Returns all elements of the source collection that return true when evaluating the predicate. This method is also commonly called filter.

      Example using a Java 8 lambda expression:

       RichIterable<Person> selected =
           people.select(person -> person.getAddress().getCity().equals("London"));
       

      Example using an anonymous inner class:

       RichIterable<Person> selected =
           people.select(new Predicate<Person>()
           {
               public boolean accept(Person person)
               {
                   return person.getAddress().getCity().equals("London");
               }
           });
       
      Specified by:
      select in interface RichIterable<K>
    • selectWith

      <P> MutableCollection<V> selectWith​(Predicate2<? super V,​? super P> predicate, P parameter)
      Description copied from interface: RichIterable
      Similar to RichIterable.select(Predicate), except with an evaluation parameter for the second generic argument in Predicate2.

      E.g. return a Collection of Person elements where the person has an age greater than or equal to 18 years

      Example using a Java 8 lambda expression:

       RichIterable<Person> selected =
           people.selectWith((Person person, Integer age) -> person.getAge()>= age, Integer.valueOf(18));
       

      Example using an anonymous inner class:

       RichIterable<Person> selected =
           people.selectWith(new Predicate2<Person, Integer>()
           {
               public boolean accept(Person person, Integer age)
               {
                   return person.getAge()>= age;
               }
           }, Integer.valueOf(18));
       
      Specified by:
      selectWith in interface RichIterable<K>
      Parameters:
      predicate - a Predicate2 to use as the select criteria
      parameter - a parameter to pass in for evaluation of the second argument P in predicate
      See Also:
      RichIterable.select(Predicate)
    • reject

      MutableCollection<V> reject​(Predicate<? super V> predicate)
      Description copied from interface: RichIterable
      Returns all elements of the source collection that return false when evaluating of the predicate. This method is also sometimes called filterNot and is the equivalent of calling iterable.select(Predicates.not(predicate)).

      Example using a Java 8 lambda expression:

       RichIterable<Person> rejected =
           people.reject(person -> person.person.getLastName().equals("Smith"));
       

      Example using an anonymous inner class:

       RichIterable<Person> rejected =
           people.reject(new Predicate<Person>()
           {
               public boolean accept(Person person)
               {
                   return person.person.getLastName().equals("Smith");
               }
           });
       
      Specified by:
      reject in interface RichIterable<K>
      Parameters:
      predicate - a Predicate to use as the reject criteria
      Returns:
      a RichIterable that contains elements that cause Predicate.accept(Object) method to evaluate to false
    • rejectWith

      <P> MutableCollection<V> rejectWith​(Predicate2<? super V,​? super P> predicate, P parameter)
      Description copied from interface: RichIterable
      Similar to RichIterable.reject(Predicate), except with an evaluation parameter for the second generic argument in Predicate2.

      E.g. return a Collection of Person elements where the person has an age greater than or equal to 18 years

      Example using a Java 8 lambda expression:

       RichIterable<Person> rejected =
           people.rejectWith((Person person, Integer age) -> person.getAge() < age, Integer.valueOf(18));
       

      Example using an anonymous inner class:

       MutableList<Person> rejected =
           people.rejectWith(new Predicate2<Person, Integer>()
           {
               public boolean accept(Person person, Integer age)
               {
                   return person.getAge() < age;
               }
           }, Integer.valueOf(18));
       
      Specified by:
      rejectWith in interface RichIterable<K>
      Parameters:
      predicate - a Predicate2 to use as the select criteria
      parameter - a parameter to pass in for evaluation of the second argument P in predicate
      See Also:
      RichIterable.select(Predicate)
    • partition

      PartitionMutableCollection<V> partition​(Predicate<? super V> predicate)
      Description copied from interface: RichIterable
      Filters a collection into a PartitionedIterable based on the evaluation of the predicate.

      Example using a Java 8 lambda expression:

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
           people.partition(person -> person.getAddress().getState().getName().equals("New York"));
       

      Example using an anonymous inner class:

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
           people.partition(new Predicate<Person>()
           {
               public boolean accept(Person person)
               {
                   return person.getAddress().getState().getName().equals("New York");
               }
           });
       
      Specified by:
      partition in interface RichIterable<K>
    • selectInstancesOf

      <S> MutableCollection<S> selectInstancesOf​(Class<S> clazz)
      Description copied from interface: RichIterable
      Returns all elements of the source collection that are instances of the Class clazz.
       RichIterable<Integer> integers =
           List.mutable.with(new Integer(0), new Long(0L), new Double(0.0)).selectInstancesOf(Integer.class);
       
      Specified by:
      selectInstancesOf in interface RichIterable<K>
    • sumByInt

      <V1> MutableObjectLongMap<V1> sumByInt​(Function<? super V,​? extends V1> groupBy, IntFunction<? super V> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByInt in interface RichIterable<K>
    • sumByFloat

      <V1> MutableObjectDoubleMap<V1> sumByFloat​(Function<? super V,​? extends V1> groupBy, FloatFunction<? super V> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByFloat in interface RichIterable<K>
    • sumByLong

      <V1> MutableObjectLongMap<V1> sumByLong​(Function<? super V,​? extends V1> groupBy, LongFunction<? super V> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByLong in interface RichIterable<K>
    • sumByDouble

      <V1> MutableObjectDoubleMap<V1> sumByDouble​(Function<? super V,​? extends V1> groupBy, DoubleFunction<? super V> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByDouble in interface RichIterable<K>
    • countBy

      default <V1> MutableBag<V1> countBy​(Function<? super V,​? extends V1> function)
      Description copied from interface: RichIterable
      This method will count the number of occurrences of each value calculated by applying the function to each element of the collection.
      Specified by:
      countBy in interface RichIterable<K>
      Since:
      9.0
    • countByWith

      default <V1,​ P> MutableBag<V1> countByWith​(Function2<? super V,​? super P,​? extends V1> function, P parameter)
      Description copied from interface: RichIterable
      This method will count the number of occurrences of each value calculated by applying the function to each element of the collection with the specified parameter as the second argument.
      Specified by:
      countByWith in interface RichIterable<K>
      Since:
      9.0
    • countByEach

      default <V1> MutableBag<V1> countByEach​(Function<? super V,​? extends Iterable<V1>> function)
      Description copied from interface: RichIterable
      This method will count the number of occurrences of each value calculated by applying the function to each element of the collection.
      Specified by:
      countByEach in interface RichIterable<K>
      Since:
      10.0.0
    • groupBy

      <V1> MutableMultimap<V1,​V> groupBy​(Function<? super V,​? extends V1> function)
      Description copied from interface: RichIterable
      For each element of the iterable, the function is evaluated and the results of these evaluations are collected into a new multimap, where the transformed value is the key and the original values are added to the same (or similar) species of collection as the source iterable.

      Example using a Java 8 method reference:

       Multimap<String, Person> peopleByLastName =
           people.groupBy(Person::getLastName);
       

      Example using an anonymous inner class:

       Multimap<String, Person> peopleByLastName =
           people.groupBy(new Function<Person, String>()
           {
               public String valueOf(Person person)
               {
                   return person.getLastName();
               }
           });
       
      Specified by:
      groupBy in interface RichIterable<K>
    • groupByEach

      <V1> MutableMultimap<V1,​V> groupByEach​(Function<? super V,​? extends Iterable<V1>> function)
      Description copied from interface: RichIterable
      Similar to RichIterable.groupBy(Function), except the result of evaluating function will return a collection of keys for each value.
      Specified by:
      groupByEach in interface RichIterable<K>
    • groupByUniqueKey

      <V1> MutableMapIterable<V1,​V> groupByUniqueKey​(Function<? super V,​? extends V1> function)
      Description copied from interface: RichIterable
      For each element of the iterable, the function is evaluated and he results of these evaluations are collected into a new map, where the transformed value is the key. The generated keys must each be unique, or else an exception is thrown.
      Specified by:
      groupByUniqueKey in interface RichIterable<K>
      See Also:
      RichIterable.groupBy(Function)
    • zip

      <S> MutableCollection<Pair<V,​S>> zip​(Iterable<S> that)
      Description copied from interface: RichIterable
      Returns a RichIterable formed from this RichIterable and another RichIterable by combining corresponding elements in pairs. If one of the two RichIterables is longer than the other, its remaining elements are ignored.
      Specified by:
      zip in interface RichIterable<K>
      Type Parameters:
      S - the type of the second half of the returned pairs
      Parameters:
      that - The RichIterable providing the second half of each result pair
      Returns:
      A new RichIterable containing pairs consisting of corresponding elements of this RichIterable and that. The length of the returned RichIterable is the minimum of the lengths of this RichIterable and that.
    • zipWithIndex

      MutableCollection<Pair<V,​Integer>> zipWithIndex()
      Description copied from interface: RichIterable
      Zips this RichIterable with its indices.
      Specified by:
      zipWithIndex in interface RichIterable<K>
      Returns:
      A new RichIterable containing pairs consisting of all elements of this RichIterable paired with their index. Indices start at 0.
      See Also:
      RichIterable.zip(Iterable)
    • aggregateInPlaceBy

      default <KK,​ VV> MutableMap<KK,​VV> aggregateInPlaceBy​(Function<? super V,​? extends KK> groupBy, Function0<? extends VV> zeroValueFactory, Procedure2<? super VV,​? super V> mutatingAggregator)
      Description copied from interface: RichIterable
      Applies an aggregate procedure over the iterable grouping results into a Map based on the specific groupBy function. Aggregate results are required to be mutable as they will be changed in place by the procedure. A second function specifies the initial "zero" aggregate value to work with (i.e. new AtomicInteger(0)).
      Specified by:
      aggregateInPlaceBy in interface RichIterable<K>
    • aggregateBy

      default <KK,​ VV> MutableMap<KK,​VV> aggregateBy​(Function<? super V,​? extends KK> groupBy, Function0<? extends VV> zeroValueFactory, Function2<? super VV,​? super V,​? extends VV> nonMutatingAggregator)
      Description copied from interface: RichIterable
      Applies an aggregate function over the iterable grouping results into a map based on the specific groupBy function. Aggregate results are allowed to be immutable as they will be replaced in place in the map. A second function specifies the initial "zero" aggregate value to work with (i.e. Integer.valueOf(0)).
      Specified by:
      aggregateBy in interface RichIterable<K>
    • aggregateBy

      default <K1,​ V1,​ V2> MutableMap<K1,​V2> aggregateBy​(Function<? super K,​? extends K1> keyFunction, Function<? super V,​? extends V1> valueFunction, Function0<? extends V2> zeroValueFactory, Function2<? super V2,​? super V1,​? extends V2> nonMutatingAggregator)
      Description copied from interface: MapIterable
      Applies an aggregate function over the map grouping results into a map based on the specific key and value groupBy functions. Aggregate results are allowed to be immutable as they will be replaced in place in the map. A second function specifies the initial "zero" aggregate value to work with.
       MapIterable<String, Interval> map = Maps.mutable.with("oneToFive", Interval.fromTo(1, 5), "sixToNine", Interval.fromTo(6, 9));
      
       MapIterable<String, Long> result = map.aggregateBy(
               eachKey -> {
                   return eachKey.equals("oneToFive")  ? "lessThanSix" : "greaterOrEqualsToSix";
               },
               each -> each.sumOfInt(Integer::intValue),
               () -> 0L,
               (argument1, argument2) -> argument1 + argument2);
      
       MapIterable<String, Long> expected =
               Maps.mutable.with("lessThanSix", Interval.fromTo(1, 5).sumOfInt(Integer::intValue),
                       "greaterOrEqualsToSix", Interval.fromTo(6, 9).sumOfInt(Integer::intValue));
       Assert.assertEquals(expected, result);
       
      Specified by:
      aggregateBy in interface MapIterable<K,​V>