/guava/guava/src/com/google/common/collect/ForwardingNavigableSet.java
return delegate ( ) .headSet ( toElement, inclusive ) ;
protected SortedSet<E> standardSubSet( @ParametricNullness E fromElement, @ParametricNullness E toElement) { return subSet(fromElement, true, toElement, false); } @Override public NavigableSet<E> headSet(@ParametricNullness E toElement, boolean inclusive) { <extra_id_0> } protected SortedSet<E> standardHeadSet(@ParametricNullness E toElement) { return headSet(toElement, false); } @Override public NavigableSet<E> tailSet(@ParametricNullness E fromElement, boolean inclusive) {