Not working with example app

[meme-lord]

App: https://github.com/BishopFox/VulnerableGWTApp

Running it against this will give the error:

Traceback (most recent call last):
  File "/home/user/gitrepos/GWTMap/./gwtmap.py", line 1048, in <module>
    main()
    ~~~~^^
  File "/home/user/gitrepos/GWTMap/./gwtmap.py", line 1041, in main
    method_objects = extract_method_info(code, service_objects)
  File "/home/user/gitrepos/GWTMap/./gwtmap.py", line 607, in extract_method_info
    "methodSignature": extract_method_signature(code, loc - 2),
                       ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/home/user/gitrepos/GWTMap/./gwtmap.py", line 547, in extract_method_signature
    parameter = parse_parameter(code, re.findall(param_pattern, code[line])[0])
                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^
IndexError: list index out of range

I think the relevant snippet of JS is:

_.checkCustomClass1_0_g$ = function ZKc_g$(cc1_0_g$, callback_0_g$) {
    var ex_0_g$, helper_0_g$, streamWriter_0_g$;
    helper_0_g$ = new Y6c_g$(this, 'CheckCustomClassService_Proxy', 'checkCustomClass1');
    try {
        streamWriter_0_g$ = helper_0_g$.start_5_g$('com.google.gwt.sample.stockwatcher.client.CheckCustomClassService', 1);
        streamWriter_0_g$.writeString_0_g$('com.google.gwt.sample.stockwatcher.client.CustomClass1/1972642674');
        streamWriter_0_g$.writeObject_0_g$(cc1_0_g$);
        helper_0_g$.finish_2_g$(callback_0_g$, (g7c_g$(), OBJECT_0_g$));
    } catch ($e0_0_g$) {
        $e0_0_g$ = UCc_g$($e0_0_g$);
        if (VBc_g$($e0_0_g$, 1160)) {
            ex_0_g$ = $e0_0_g$;
            callback_0_g$.onFailure_1_g$(ex_0_g$);
        } else
            throw VCc_g$($e0_0_g$);
    }
};