title: How to use Hibernate validation annotations with enums?
body: <p>How can I use hibernate annotations to validate an enum member field?
  The following does not work:</p>
  
  <pre><code>enum UserRole {
     USER, ADMIN;
  }
  
  class User {
     @NotBlank //HV000030: No validator could be found for type: UserRole.
     UserRole userRole;
  }
  </code></pre>