length should correctly use the maximum number of parameters, which i…

…s present in the wrapper prototype method, and may not be there in the base class implementation.

lib/wrapper/client_wrapper.js

@@ -78,7 +78,7 @@ module.exports = function(name,base_client,transform, provider_config, credentia
         //TODO: pop the filefog variable off the args object, it should only be used to configure Filefog.
         var self = this;
         try{
-            var expected_parameters = ClientWrapper.super_.prototype[method].length;
+            var expected_parameters = ClientWrapper.prototype[method].length;
             if((expected_parameters-1) >= 0){
                 //filefog_options is always the last parameter.
                 args = Array.prototype.slice.call(args)