def add_title(self, title, width=None, height=None, fontsize=11):
        r"""
        Add a title item to the current sheet.
        Note that the current method only add a new item to the list of items to be generated.
        The report Excel file is generated only when the :py:obj:`~ExcelReport.to_excel` is called.

        Parameters
        ----------
        title : str
            Text to write in the title item.
        width : int, optional
            width of the title item. The current default value is used if None
            (see :py:obj:`~ExcelReport.set_item_default_size`). Defaults to None.
        height : int, optional
            height of the title item. The current default value is used if None
            (see :py:obj:`~ExcelReport.set_item_default_size`). Defaults to None.
        fontsize : int, optional
            fontsize of the displayed text. Defaults to 11.

        Examples
        --------
        >>> report = ExcelReport()

        >>> first_sheet = report.new_sheet('First_sheet')
        >>> first_sheet.add_title('Title banner with default width, height and fontsize')
        >>> first_sheet.add_title('Larger title banner', width=1200, height=100)
        >>> first_sheet.add_title('Bigger fontsize', fontsize=13)

        >>> # do not forget to call 'to_excel' to create the report file
        >>> report.to_excel('Report.xlsx')
        """
        pass