code: def set_right_margin(self, right_margin):
          
          self.__header.style.margins.right = right_margin
          self.__prologue.style.margins.right = right_margin
          self.__items_section.style.margins.right = right_margin
          self.__epilogue.style.margins.right = right_margin
          self.__footer.style.margins.right = right_margin
          self.__prompt.style.margins.right = right_margin
          return self
docs: Set the right margin of the menu.  This will determine the number of spaces between the right edge of the
          screen and the right menu border.
          :param right_margin: an integer value