def garbage_collect(self):
        """Delete cells that are not storing a value."""
        delete_list = [coordinate for coordinate, cell in \
            self._cells.items() if (('', None) in cell.value and \
            hash(cell.style) == _DEFAULTS_STYLE_HASH)]
        for coordinate in delete_list:
            del self._cells[coordinate]
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/tablib-0.10.0/tablib/packages/openpyxl/worksheet.py/Worksheet.garbage_collect/swapped operands of `in`