code: @Override
      public V get(Object key) {
          int hash = this.hashOf(key);
          return this.segmentFor(hash).get(key, hash);
      }
docs: Returns the value to which the specified key is mapped, or {@code null}
  if this map contains no mapping for the key.
  
  <p>
  More formally, if this map contains a mapping from a key {@code k} to a
  value {@code v} such that {@code key.equals(k)}, then this method returns
  {@code v}; otherwise it returns {@code null}. (There can be at most one
  such mapping.)
  
  @throws NullPointerException
  if the specified key is null