docs: protected String determineProfileBinding(final Pair<AuthnRequest, MessageContext> authenticationContext,
                                               final Assertion assertion) {
  
          val authnRequest = authenticationContext.getKey();
          val pair = getRegisteredServiceAndFacade(authnRequest);
          val facade = pair.getValue();
  
          val binding = StringUtils.defaultIfBlank(authnRequest.getProtocolBinding(), SAMLConstants.SAML2_POST_BINDING_URI);
          LOGGER.debug("Determined authentication request binding is [{}], issued by [{}]", binding, authnRequest.getIssuer().getValue());
  
          val entityId = facade.getEntityId();
          LOGGER.debug("Checking metadata for [{}] to see if binding [{}] is supported", entityId, binding);
          val svc = facade.getAssertionConsumerService(binding);
          LOGGER.debug("Binding [{}] is supported by [{}]", svc.getBinding(), entityId);
          return binding;
      }