code: private boolean isAccessPrecluded(HttpConstraintElement httpConstraint) {
          boolean accessPrecluded = false;
          String[] roles = httpConstraint.getRolesAllowed();
          if (roles == null || roles.length == 0) {
              if (EmptyRoleSemantic.DENY == httpConstraint.getEmptyRoleSemantic())
                  accessPrecluded = true;
          }
          return accessPrecluded;
      }
docs: Determines if access is precluded for the given HTTP constraint.
  
  Access is precluded when there are no roles, and the emptyRoleSemantic
  defined in the annotation is DENY.
  
  @param httpConstraint the element representing the information in the @HttpConstraint annotation
  @return true if access is precluded, otherwise false