/guava/guava/src/com/google/common/graph/Traverser.java
if ( top.hasNext( ) ) {   return checkNotNull( top.next( ) ) ; }
[Delete]
return new Traversal<N>(tree) { @CheckForNull @Override N visitNext(Deque<Iterator<? extends N>> horizon) { Iterator<? extends N> top = horizon.getFirst(); if (top.hasNext()) { <extra_id_0> } horizon.removeFirst(); return null; } }; }