def METHOD_NAME():
    parser = argparse.ArgumentParser(
        "pvacfuse generate_protein_fasta",
        description="Generate an annotated fasta file from AGFusion or Arriba output.",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter
    )
    parser.add_argument(
        "input",
        help="An AGFusion output directory or Arriba fusion.tsv output file."
    )
    parser.add_argument(
        "flanking_sequence_length", type=int,
        help="Number of amino acids to add on each side of the mutation when creating the FASTA.",
    )
    parser.add_argument(
        "output_file",
        help="The output fasta file."
    )
    parser.add_argument(
        "--input-tsv",
        help = "A pVACfuse all_epitopes or filtered TSV file with epitopes to use for subsetting the input file to peptides of interest. Only the peptide sequences for the epitopes in the TSV will be used when creating the FASTA."
    )
    parser.add_argument(
        "-d", "--downstream-sequence-length",
        default="1000",
        help="Cap to limit the downstream sequence length for frameshift fusion when creating the fasta file. "
            + "Use 'full' to include the full downstream sequence."
    )
    return parser