def setup(self):
        """Performs necessary setup to begin exporting media.

        :class:`DatasetExporter` classes using this class should invoke this
        method in :meth:`DatasetExporter.setup`.
        """
        output_dir = None
        manifest_path = None
        manifest = None

        if self.export_mode in (True, "move", "symlink"):
            output_dir = self.export_path
        elif self.export_mode == "manifest":
            manifest_path = self.export_path
            manifest = {}

        # Not multi-process safe when user chunk size
        self._filename_maker = fou.UniqueFilenameMaker(
            output_dir=output_dir,
            rel_dir=self.rel_dir,
            chunk_size=self.chunk_size,
            default_ext=self.default_ext,
            ignore_exts=self.ignore_exts,
            ignore_existing=True,
        )
        self._manifest_path = manifest_path
        self._manifest = manifest
Performs necessary setup to begin exporting media.

        :class:`DatasetExporter` classes using this class should invoke this
        method in :meth:`DatasetExporter.setup`.
        
fiftyone/utils/data/exporters.py