def __init__(
        self,
        numpy_data: np.ndarray,
        numpy_key: str = "features",
        dict_transform: Optional[Callable] = None,
    ):
        """
        General purpose dataset class to use with `numpy_data`.

        Args:
            numpy_data: numpy data
              (for example path to embeddings, features, etc.)
            numpy_key: key to use for output dictionary
            dict_transform: transforms to use on dict.
              (for example normalize vector, etc)
        """
        super().__init__()
        self.data = numpy_data
        self.key = numpy_key
        self.dict_transform = (
            dict_transform if dict_transform is not None else lambda x: x
        )

        General purpose dataset class to use with `numpy_data`.

        Args:
            numpy_data: numpy data
              (for example path to embeddings, features, etc.)
            numpy_key: key to use for output dictionary
            dict_transform: transforms to use on dict.
              (for example normalize vector, etc)
        
catalyst/contrib/data/dataset.py