for (Context c : Context.getContexts()) {
    updateCount += c.validateModel(update);
}

public static synchronized Collection<Context> getContexts() {
    ....
    return Collections.unmodifiableCollection(new ArrayList<Context>(contextMapByID.values()));
}

public class A {
    public static void main(String[] args) {
        for (String a : B.getAll()) {
            System.out.println(a);
        }
    }
}

import java.util.Collection;
import java.util.ArrayList;

public class B {
    static Collection<String> all = new ArrayList<String>();
    public static Collection<String> getAll() {
        return all;
    }
}

...
for(String line: file.getFileContents()){
...

public List<String> getFileContents() {
   return fileContents;
}

import java.util.ArrayList;
import java.util.List;


public class Test {
	
	private static List<String> getList(){
		return new ArrayList<String>();
	}
	
	public static void main(String [] args){
		for(String line: getList()){
			System.out.println(line);
		}
	}
}