Here you can find the source of convertIterable(final Iterable extends Iterable> iterables)
public static <U> Iterable<Iterator<U>> convertIterable(final Iterable<? extends Iterable<U>> iterables)
//package com.java2s; //License from project: Apache License import java.util.Iterator; import java.util.LinkedList; import java.util.List; public class Main { public static <U> Iterable<Iterator<U>> convertIterable(final Iterable<? extends Iterable<U>> iterables) { final List<Iterator<U>> iterators = new LinkedList<>(); for (Iterable<U> i : iterables) { iterators.add(i.iterator()); }/*from w w w. j a v a2 s .co m*/ return iterators; } }