Create a sheet with the given title. This does not check if
        another sheet by the same name already exists.

def create_sheet(self, title):
        """ Create a sheet with the given title. This does not check if
        another sheet by the same name already exists. """
        ws = self.conn.sheets_service.AddWorksheet(title, 10, 10, self.id)
        self._wsf = None
        return Sheet(self, ws)