def METHOD_NAME(self):
    # Add a vbaProject to the ContentTypes defaults.
    # Change the workbook.xml content-type from xlsx to xlsm.
    for i, override in enumerate(self.overrides):
        if override[0] == '/xl/workbook.xml':
            self.overrides[i][1] = 'application/vnd.ms-excel.' \
                'sheet.macroEnabled.main+xml'
    self._add_default(('bin', 'application/vnd.ms-office.vbaProject'))