docs: def fill_rect(self, rect):
          """Fill a rectangle on the current rendering target with the drawing color.
  
          Args:
              rect (Rect): The destination rectangle, or None to fill the entire rendering target.
  
          Raises:
              SDLError: If an error is encountered.
          """
          check_int_err(lib.SDL_RenderFillRect(self._ptr, rect._ptr))