private Predicate createUserPrivilegePredicate(String username) {
    return new EqualsPredicate<>(UserPrivilegeResourceProvider.USER_NAME, username);
  }
Create a predicate to use to query for the user's set of privileges

@param username the username of the relevant user
@return a predicate
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/UserAuthorizationResourceProvider.java