/**
  * @param AssertionContext $context
  *
  * @return void
  */
 protected function doExecute(AssertionContext $context)
 {
     if (null === $context->getAssertion()->getIssuer()) {
         $message = 'Assertion element must have an issuer element';
         $this->logger->error($message, LogHelper::getActionErrorContext($context, $this));
         throw new LightSamlContextException($context, $message);
     }
     if (false == $this->idpEntityDescriptorProvider->has($context->getAssertion()->getIssuer()->getValue())) {
         $message = sprintf("Unknown issuer '%s'", $context->getAssertion()->getIssuer()->getValue());
         $this->logger->error($message, LogHelper::getActionErrorContext($context, $this, ['messageIssuer' => $context->getAssertion()->getIssuer()->getValue()]));
         throw new LightSamlContextException($context, $message);
     }
     $this->logger->debug(sprintf('Known assertion issuer: "%s"', $context->getAssertion()->getIssuer()->getValue()), LogHelper::getActionContext($context, $this));
 }