def load(self, filename, create_if_missing=True):
        filename = Path(filename)
        if not filename.exists() and create_if_missing:
            self.load_pip_requirements()
            with filename.open("w") as f:
                f.write(yaml.dump(self.serialized, default_flow_style=False,
                                  encoding=None))
            self.filename = filename
            return self.save(filename)
        with filename.open() as f:
            for group, requirements in yaml.load(f.read()).items():
                for requirement in requirements:
                    self[group].add(Requirement.coerce(requirement))
        self.filename = filename
def flush_to_index(self) -> None:
        """Flush changes in our configuration file to the index"""
        assert self._smref is not None
        # should always have a file here
        assert not isinstance(self._file_or_files, BytesIO)

        sm = self._smref()
        if sm is not None:
            index = self._index
            if index is None:
                index = sm.repo.index
            # END handle index
            index.add([sm.k_modules_file], write=self._auto_write)
            sm._clear_cache()
        # END handle weakref