code: protected function applyChainForGet($key, $subject)
      {
          foreach ($this->accessors as $accessor) {
              if ($accessor->canAccessForRead($key, $subject)) {
                  return $accessor->get($key, $subject);
              }
          }
  
          throw new \InvalidArgumentException(
              'Don\'t know how to get "' . $key . '" in "' .
              (is_object($subject) ? get_class($subject) : gettype($subject)) . '"'
          );
      }
docs: @param string $key
  @param mixed  $subject
  
  @return mixed