code: @SuppressWarnings({"ThrowableInstanceNeverThrown"})
      public static void validateVoid(Method method, List<Throwable> errors)
      {
          if (method.getReturnType() != Void.TYPE)
          {
              errors.add(new Exception("Method " + method.getName() + "() should be void"));
          }
      }
docs: Validate that a method returns no value.
  
  @param method the method to be tested
  @param errors a list to place the errors