code: @SuppressWarnings("unchecked")
      public static <U> Tuple<U> of(Object red, Object black, Object redCopy) {
          return new Tuple<>((U)red, (U)black, (U)redCopy);
      }
docs: Factory method that turns three untyped values into a typed tuple.
  
  @param red The red value.
  @param black The black value.
  @param redCopy A shallow copy of the red value.
  @param <U> The assumed type of the values.
  @return A typed tuple with the three given values.