def new_sheet(self, sheet_name):
        r"""
        Add a new empty output sheet.
        This sheet will contain only graphical elements, all data are exported
        to a dedicated separate sheet.

        Parameters
        ----------
        sheet_name : str
            name of the current sheet.

        Returns
        -------
        sheet: ReportSheet

        Examples
        --------
        >>> demo = load_example_data('demography_eurostat')
        >>> report = ExcelReport(EXAMPLE_EXCEL_TEMPLATES_DIR)

        >>> # prepare new output sheet named 'Belgium'
        >>> sheet_be = report.new_sheet('Belgium')

        >>> # add graph to the output sheet 'Belgium'
        >>> sheet_be.add_graph(demo.population['Belgium'], 'Population', template='Line')
        """
        pass