code: protected boolean isIssuedAuthnContextClassRefAccepted(ProfileRequestContext<?, ?> context, String authnContextUri) {
  
      try {
        List<String> requested = this.getAuthnContextClassContext(context).getProxiedAuthnContextClassRefs();
        if (requested == null || requested.isEmpty()) {
          // If we did not request anything, we accept what we got.
          return true;
        }
        return requested.contains(authnContextUri);
      }
      catch (ExternalAutenticationErrorCodeException e) {
        // Will fail later
        return false;
      }
    }
docs: Depending on the type of matching of AuthnContextClassRef URI:s that is used we check whether an issued URI is what
  we can accept (corresponds to what we requested).
  <p>
  The default implementation used "exact" matching.
  </p>
  
  @param context
  the request context
  @param authnContextUri
  the URI received in the assertion from the remote IdP
  @return if the URI is accepted {@code true} is returned, otherwise {@code false}