def METHOD_NAME(fs_: bytes) -> bytes:
    """
    Detection of the wear levelling layer is performed in two steps:
    1) check if the first sector is a valid boot sector
    2) check if the size defined in the boot sector is the same as the partition size:
        - if it is, there is no wear levelling layer
        - otherwise, we need to remove wl for further processing
    """
    try:
        boot_sector__ = BootSector()
        boot_sector__.parse_boot_sector(fs_)
        if boot_sector__.boot_sector_state.size == len(fs_):
            return fs_
    except construct.core.ConstError:
        pass
    plain_fs: bytes = remove_wl(fs_)
    return plain_fs