/guava/guava/src/com/google/common/collect/HashBiMap.java
if ( oldEntryForKey == null) {
if ( oldEntryForValue != null ) {
BiEntry<K, V> newEntry = new BiEntry<>(key, keyHash, value, valueHash); insert(newEntry, oldEntryForKey); if (oldEntryForKey != null) { oldEntryForKey.prevInKeyInsertionOrder = null; oldEntryForKey.nextInKeyInsertionOrder = null; } <extra_id_0> oldEntryForValue.prevInKeyInsertionOrder = null; oldEntryForValue.nextInKeyInsertionOrder = null; } rehashIfNecessary(); return Maps.keyOrNull(oldEntryForValue); }