Return all operations stored in containers.

def op_paths(self, path_base):
        # type: (Union[str, UrlPath]) -> Generator[Tuple[UrlPath, Operation]]
        """
        Return all operations stored in containers.
        """
        path_base += self.path_prefix

        for operation in self._operations:
            for op_path in operation.op_paths(path_base):
                yield op_path