def METHOD_NAME(self, part_strings):
    """
    Underline and title case command line help message headers.
    """
    if part_strings and part_strings[0].startswith("usage: "):
        part_strings[0] = "Usage\n=====\n  " + part_strings[0][len("usage: ") :]
    headings = [
        i for i in range(len(part_strings)) if part_strings[i].endswith(":\n")
    ]
    for index in headings[::-1]:
        char = "-" if "Global Options" in part_strings[index] else "="
        part_strings[index] = part_strings[index][:-2].title()
        underline = "".join(["\n", (char * len(part_strings[index])), "\n"])
        part_strings.insert(index + 1, underline)
    return part_strings