def METHOD_NAME(manifest_obj):
    # check the 'in' operator
    sigfile = utils.get_test_data('prot/dayhoff/GCA_001593925.1_ASM159392v1_protein.faa.gz.sig')
    ss = sourmash.load_one_signature(sigfile)
    assert ss in manifest_obj
    sigfile2 = utils.get_test_data('2.fa.sig')
    ss2 = sourmash.load_one_signature(sigfile2, ksize=31)
    assert ss2 not in manifest_obj