str: func_name(type1,type2) returns (type3)
            Return the function signature as a str (contains the return values)

def signature_str(self):
        """
            str: func_name(type1,type2) returns (type3)
            Return the function signature as a str (contains the return values)
        """
        name, parameters, returnVars = self.signature
        return name+'('+','.join(parameters)+') returns('+','.join(returnVars)+')'