pose-estimation>`_ dataset.

    The dataset is expected to have the following structure: ::

        root
            FallingThings
                single
                    dir1
                        scene1
                            _object_settings.json
                            _camera_settings.json
                            image1.left.depth.png
                            image1.right.depth.png
                            image1.left.jpg
                            image1.right.jpg
                            image2.left.depth.png
                            image2.right.depth.png
                            image2.left.jpg
                            image2.right
                            ...
                        scene2
                    ...
                mixed
                    scene1
                        _object_settings.json
                        _camera_settings.json
                        image1.left.depth.png
                        image1.right.depth.png
                        image1.left.jpg
                        image1.right.jpg
                        image2.left.depth.png
                        image2.right.depth.png
                        image2.left.jpg
                        image2.right
                        ...
                    scene2
                    ...

    Args:
        root (string): Root directory where FallingThings is located.
        variant (string): Which variant to use. Either "single", "mixed", or "both".
        transforms (callable, optional): A function/transform that takes in a sample and returns a transformed version.
    