Keep all specified subplots completely empty.

        :param row_column_list: a list containing (row, column) tuples to
            specify the subplots, or None to indicate *all* subplots.
        :type row_column_list: list or None

def set_empty_for_all(self, row_column_list):
        """Keep all specified subplots completely empty.

        :param row_column_list: a list containing (row, column) tuples to
            specify the subplots, or None to indicate *all* subplots.
        :type row_column_list: list or None

        """
        for row, column in row_column_list:
            self.set_empty(row, column)