def Xdump_all(self, documents, stream, _kw=enforce, transform=None):
        # type: (Any, Union[Path, StreamType], Any, Any) -> Any
        """
        Serialize a sequence of Python objects into a YAML stream.
        """
        if not hasattr(stream, 'write') and hasattr(stream, 'open'):
            # pathlib.Path() instance
            with stream.open('w') as fp:
                return self.dump_all(documents, fp, _kw, transform=transform)
        if _kw is not enforce:
            raise TypeError(
                '{}.dump(_all) takes two positional argument but at least '
                'three were given ({!r})'.format(self.__class__.__name__, _kw)
            )
        # The stream should have the methods `write` and possibly `flush`.
        if self.top_level_colon_align is True:
            tlca = max([len(str(x)) for x in documents[0]])  # type: Any
        else:
            tlca = self.top_level_colon_align
        if transform is not None:
            fstream = stream
            if self.encoding is None:
                stream = StringIO()
            else:
                stream = BytesIO()
        serializer, representer, emitter = self.get_serializer_representer_emitter(
            stream, tlca
        )
        try:
            self.serializer.open()
            for data in documents:
                try:
                    self.representer.represent(data)
                except AttributeError:
                    # nprint(dir(dumper._representer))
                    raise
            self.serializer.close()
        finally:
            try:
                self.emitter.dispose()
            except AttributeError:
                raise
                # self.dumper.dispose()  # cyaml
            delattr(self, '_serializer')
            delattr(self, '_emitter')
        if transform:
            val = stream.getvalue()
            if self.encoding:
                val = val.decode(self.encoding)
            if fstream is None:
                transform(val)
            else:
                fstream.write(transform(val))
        return None

        Serialize a sequence of Python objects into a YAML stream.
        
dynaconf/vendor/ruamel/yaml/main.py