code: @NotNull
      public IntStream peek(@NotNull final IntConsumer action) {
          return new IntStream(params, new IntPeek(iterator, action));
      }
docs: Returns a stream consisting of the elements of this stream, additionally
  performing the provided action on each element as elements are consumed
  from the resulting stream. Handy method for debugging purposes.
  
  <p>This is an intermediate operation.
  
  @param action the action to be performed on each element
  @return the new stream