def __init__(self, array, split_path: str, hash_data: Hashable, plasma_path=None):
        """
        Args:
            array: numpy array to store. This can be read with ``PlasmaView().array``
            split_path: the path whence the data was read, used for hashing
            hash_data: other metadata about the array that can be used to create a unique key.
                as of writing, the 3 callers in ``TokenBlockDataset`` use::

                    hash_data = ((block_size, document_sep_len, str(break_mode), len(dataset)), 0|1|2)


        """
        assert PYARROW_AVAILABLE
        assert split_path is not None
        if plasma_path is None:
            plasma_path = DEFAULT_PLASMA_PATH

        self.path = plasma_path
        self.split_path = split_path
        self._client = None  # Initialize lazily for pickle. plasma clients should not be deep copied or serialized.
        self._n = None

        self.object_id = self.get_object_id(self.split_path, hash_data)
        try:
            self.client.put(array, object_id=self.object_id)
        except plasma.PlasmaObjectExists:
            pass

        Args:
            array: numpy array to store. This can be read with ``PlasmaView().array``
            split_path: the path whence the data was read, used for hashing
            hash_data: other metadata about the array that can be used to create a unique key.
                as of writing, the 3 callers in ``TokenBlockDataset`` use::

                    hash_data = ((block_size, document_sep_len, str(break_mode), len(dataset)), 0|1|2)


        
understand_icl/fairseq/fairseq/data/plasma_utils.py