def aligner_indices_fake_fs(fake_fs):
    """Return fake file system setup with files for aligner indices"""
    d = {
        "bwa": (".fasta.amb", ".fasta.ann", ".fasta.bwt", ".fasta.pac", ".fasta.sa"),
        "star": ("/Genome", "/SA", "/SAindex"),
    }
    for aligner, suffixes in d.items():
        for suffix in suffixes:
            fake_fs.fs.create_file("/path/to/{}/index{}".format(aligner, suffix))
    return fake_fs