def get_raw_read_name(alignment: bytes, read_name_length: int) ->bytes:
    """Extract the raw readname from a BAM alignment bytestring

    Parameters
    ----------
    alignment : bytes
        A byte string of a bam alignment entry in raw binary format

    len_read_name : int
        The length of the readname string
        eg from pylazybam.bam.get_len_read_name()

    Returns
    -------
    bytes
        The raw base readname in BAM format as a binary bytestring

    """
    return alignment[36:36 + read_name_length]
