/guava/android/guava/src/com/google/common/collect/Maps.java
return ( SortedSet<K> ) tailMap ( fromElement ) .keySet ( ) ;
@Override public SortedSet<K> headSet(@ParametricNullness K toElement) { return (SortedSet<K>) headMap(toElement).keySet(); } @Override public SortedSet<K> tailSet(@ParametricNullness K fromElement) { <extra_id_0> } @Override @ParametricNullness public K first() { return firstKey(); }