code: @Pure
  	public static <K, V> Pair<K, V> of(K k, V v) {
  		return new Pair<K, V>(k, v);
  	}
docs: Creates a new instance with the given key and value.
  May be used instead of the constructor for convenience reasons.
  
  @param k
  the key. May be <code>null</code>.
  @param v
  the value. May be <code>null</code>.
  @return a newly created pair. Never <code>null</code>.
  @since 2.3