def METHOD_NAME(manifest_filename):
    # Determine the filenames of all the output files from the manifest
    print(f"\nManifest Filename: {manifest_filename}")
    files = []
    with open(manifest_filename, 'r') as fout:
        for line in fout.readlines():
            files.append(line.rstrip('\n'))
    print("\ngather_output_data. Output data files: {}".format(files))
    return files