code: public static boolean isMain(MethodGen mg) {
      Type[] argTypes = mg.getArgumentTypes();
      return mg.isStatic()
          && (mg.getReturnType() == Type.VOID)
          && mg.getName().equals("main")
          && (argTypes.length == 1)
          && argTypes[0].equals(stringArray);
    }
docs: Returns whether or not this is a standard main method (static, void, name is 'main', and one
  formal parameter: a string array).
  
  @param mg the method to check
  @return true iff the method is a main method