code: public ConstantMethodInfo addConstantMethod(String className,
                                                  String methodName,
                                                  TypeDesc ret,
                                                  TypeDesc[] params) {
          
          MethodDesc md = MethodDesc.forArguments(ret, params);
          ConstantInfo ci = new ConstantMethodInfo
              (addConstantClass(className), addConstantNameAndType(methodName, md));
          return (ConstantMethodInfo)addConstant(ci);
      }
docs: Get or create a constant from the constant pool representing a method
  in any class. If the method returns void, set ret to null.