All of the `setValue` methods note:

     * <p>
     * Note that the preferred way of re-initializing a preference to its
     * default value is to call <code>setToDefault</code>.
     * </p>

The IPreferenceStore interface represents a table mapping named preferences to values. If there is no value for a given name, then that preferences's default value is returned; and if there is no default value for that preference, then a default-default value is returned. The default-default values for the primitive types are as follows:

Removing a value means reverting the value to the default value.