human
Solve the following python programming problem given the following code:
def main() : 
    usagestr = 'usage: %prog [-h] [options] [args]' 
    parser = optparse.OptionParser (usage = usagestr) 
    parser.set_defaults (numnodes = 2, enablesdt = False, sdturl = 'tcp://127.0.0.1:50000/') 
    parser.add_option ('-n', '--numnodes', dest = 'numnodes', type = int, help = ('number of nodes to test.
default = %s' % parser.defaults ['numnodes'])) 
    parser.add_option ('-s', '--sdt', dest = 'enablesdt', action = 'store_true', help = 'enable SDT output') 
    parser.add_option ('-u', '--sdturl', dest = 'sdturl', type = 'string', help = ('URL for SDT connection, default = %s' % start.defaults ['sdturl'])) 
    def usage(msg = None, err = 0) : 
        sys.stdout.write ('
') 
        if msg : 
            sys.stdout.write ((msg + '

')) 
parser.print_help () 
        sys.exit (err) 
(options, args) = parser.parse_args () 
    if (options.numnodes < 2) : 
        usage (('invalid number of nodes: %s' % options.numnodes)) 
for a in args : 
        sys.stderr.write (("ignoring command line argument: '%s'
" % a)) 
start = datetime.datetime.now () 
    test (options) 
    ((print >> sys.stderr), ('elapsed time: %s' % (datetime.datetime.now () - start))) 

    
    

    Fix the buggy line: parser.add_option ('-u', '--sdturl', dest = 'sdturl', type = 'string', help = ('URL for SDT connection, default = %s' % start.defaults ['sdturl']))
assistant
#Here is Python code to fix the buggy line: parser.

parser.add_option ('-u', '--sdturl', dest = 'sdturl', type = 'string', help = ('URL for SDT connection, default = %s' % parser.defaults ['sdturl']))