public V fill(K key,V value){
  return fill(key,value,0);
}

public V fill ( K key , V value ) { return fill ( key , value , 0 ) ; }
associates the specified value with the specified key in this map . if the map does not contain a mapping for the key , the new mapping is only installed if there is room . if the map previously contained a mapping for the key , the old value is replaced by the specified value even if this results in a failure or eviction .
