code: @Override
      protected URI getEndpointURL(MessageContext<SAMLObject> messageContext) throws MessageEncodingException {
          try {
              return SAMLBindingSupport.getEndpointURL(messageContext);
          } catch (BindingException e) {
              throw new MessageEncodingException("Could not obtain message endpoint URL", e);
          }
      }
docs: Gets the response URL from the message context.
  
  @param messageContext current message context
  @return response URL from the message context
  @throws MessageEncodingException throw if no relying party endpoint is available