Convert Iterable<Entity> to Entity<Key>

EntityToKeyIterable.java

import java.util.Iterator;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.Key;

public class EntityToKeyIterable implements Iterable<Key> {
  Iterable<Entity> iterable;
  public EntityToKeyIterable(Iterable<Entity> iterable) {
    this.iterable = iterable;
  }
  @Override
  public Iterator<Key> iterator() {
    return new EntityToKeyIterator(iterable.iterator());
  }
  protected class EntityToKeyIterator implements Iterator<Key> {
    Iterator<Entity> it;
    public EntityToKeyIterator(Iterator<Entity> it) {
      this.it = it;
    }
    @Override
    public boolean hasNext() {
      return it.hasNext();
    }
    @Override
    public Key next() {
      return it.next().getKey();
    }
    @Override
    public void remove() {
      it.remove();
    }    
  }
}