code: private static Optional<StandardMethod> maybeStandardMethod(ExecutableElement method) {
      String methodName = method.getSimpleName().toString();
      if (methodName.equals("equals")) {
        if (method.getParameters().size() == 1
            && method.getParameters().get(0).asType().toString().equals("java.lang.Object")) {
          return Optional.of(StandardMethod.EQUALS);
        } else {
          return Optional.empty();
        }
      } else if (methodName.equals("hashCode")) {
        if (method.getParameters().isEmpty()) {
          return Optional.of(StandardMethod.HASH_CODE);
        } else {
          return Optional.empty();
        }
      } else if (methodName.equals("toString")) {
        if (method.getParameters().isEmpty()) {
          return Optional.of(StandardMethod.TO_STRING);
        } else {
          return Optional.empty();
        }
      } else {
        return Optional.empty();
      }
    }
docs: Returns whether a method is one of the {@link StandardMethod}s, and if so, which.