/guava/guava/src/com/google/common/collect/AbstractBiMap.java
boolean containedKey = checkKey( key) ;
boolean containedKey = containsKey ( key ) ;
return putInBothMaps(key, value, true); } @CheckForNull private V putInBothMaps(@ParametricNullness K key, @ParametricNullness V value, boolean force) { checkKey(key); checkValue(value); <extra_id_0> if (containedKey && Objects.equal(value, get(key))) { return value; } if (force) { inverse().remove(value); } else {