selfchunks, providing info on index and special values.
info (namedtuple) – A namedtuple with the following fields: nchunk: the index of the chunk (int). coords: the coordinates of the chunk, in chunk units (tuple). cratio: the compression ratio of the chunk (float). special: the special value enum of the chunk; if 0, the chunk is not special (SpecialValue). repeated_value: the repeated value for the chunk; if not SpecialValue.VALUE, it is None. lazychunk: a buffer with the complete lazy chunk (bytes).