def write(self, writer, sheet_name='Sheet1', startrow=0,
              startcol=0, freeze_panes=None, engine=None):
        """
        writer : string or ExcelWriter object
            File path or existing ExcelWriter
        sheet_name : string, default 'Sheet1'
            Name of sheet which will contain DataFrame
        startrow :
            upper left cell row to dump data frame
        startcol :
            upper left cell column to dump data frame
        freeze_panes : tuple of integer (length 2), default None
            Specifies the one-based bottommost row and rightmost column that
            is to be frozen
        engine : string, default None
            write engine to use if writer is a path - you can also set this
            via the options ``io.excel.xlsx.writer``, ``io.excel.xls.writer``,
            and ``io.excel.xlsm.writer``.
        """
        from pandas.io.excel import ExcelWriter
        from pandas.io.common import _stringify_path

        if isinstance(writer, ExcelWriter):
            need_save = False
        else:
            writer = ExcelWriter(_stringify_path(writer), engine=engine)
            need_save = True

        formatted_cells = self.get_formatted_cells()
        writer.write_cells(formatted_cells, sheet_name,
                           startrow=startrow, startcol=startcol,
                           freeze_panes=freeze_panes)
        if need_save:
            writer.save()