def _shape2xls(self, worksheets):
        """Writes shape to xls file

        Format: <rows>\t<cols>\t<tabs>\n

        """

        __, __, tabs = self.code_array.shape

        if tabs > self.xls_max_tabs:
            tabs = self.xls_max_tabs

        for tab in xrange(tabs):
            worksheet = self.workbook.add_sheet(str(tab))
            worksheets.append(worksheet)
Writes shape to xls file

        Format: <rows>\t<cols>\t<tabs>\n