/guava/android/guava/src/com/google/common/collect/Synchronized.java
if ( ( keySet) == null) {   keySet = typePreservingSet( delegate( ).keySet( ) , mutex) ; }
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BiMap<K, V> delegate() { return (BiMap<K, V>) super.delegate(); } @Override public Set<V> values() { synchronized (mutex) { <extra_id_0> valueSet = set(delegate().values(), mutex); } return valueSet; } } @Override