def isref(self) -> IsrefRequestBuilder:
        """
        Provides operations to call the isref method.
        """
        from .isref.isref_request_builder import IsrefRequestBuilder

        return IsrefRequestBuilder(self.request_adapter, self.path_parameters)

        Provides operations to call the isref method.
        
msgraph/generated/drives/item/items/item/workbook/functions/functions_request_builder.py