def create(cls, mr_spec, shard_number, shard_attempt, _writer_state=None):
    """Inherit docs."""
    writer_spec = cls.get_params(mr_spec.mapper, allow_old=False)

    # Determine parameters
    key = cls._generate_filename(writer_spec, mr_spec.name,
                                 mr_spec.mapreduce_id,
                                 shard_number, shard_attempt)

    status = _ConsistentStatus()
    status.writer_spec = writer_spec
    status.mainfile = cls._open_file(writer_spec, key)
    status.mapreduce_id = mr_spec.mapreduce_id
    status.shard = shard_number

    return cls(status)
Inherit docs.