code: public void validatePublicVoidNoArg(boolean isStatic, List<Throwable> errors) {
          validatePublicVoid(isStatic, errors);
          if (method.getParameterTypes().length != 0) {
              errors.add(new Exception("Method " + method.getName() + " should have no parameters"));
          }
      }
docs: Adds to {@code errors} if this method:
  <ul>
  <li>is not public, or
  <li>takes parameters, or
  <li>returns something other than void, or
  <li>is static (given {@code isStatic is false}), or
  <li>is not static (given {@code isStatic is true}).
  </ul>