<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def main():
 """ Testing function for Flex Regular Expressions to FST DFA """

    if len(argv) < 2:
        print 'Usage: %s fst_file [optional: save_file]' % argv[0]
        return
    flex_a = Flexparser()
    mma = flex_a.yyparse(argv[1])
    mma.minimize()
    print mma
    if len(argv) == 3:
        mma.save(argv[2])