Error when using metavar with nargs

The test below requests two integers and adds them up. When using argparse, I use a tuple metavar to name each value so the user can tell that they represent different things. Gooey doesn't like this and raises a TypeError in components.py:format_title(). Using a GooeyParser doesn't help. Replacing the metavar tuple with a single string works.

Could we tweak the format_title method to accept a tuple of strings?

from argparse import ArgumentParser
from gooey import Gooey
    
@Gooey
def main_argparse():
    parser = ArgumentParser(description='Sum two integers.')
    parser.add_argument('integers', type=int, nargs=2, metavar=('first', 'second'))
    
    args = parser.parse_args()
    print sum(args.integers)
        
if __name__=="__main__":
    #main_argparse()
    main_gooey()