code: public function create($action)
      {
          $actionName = ucfirst($action);
          $class = sprintf('RedKiteCms\Content\BlockManager\BlockManager%s', $actionName);
  
          if (!class_exists($class)) {
              return null;
          }
  
          $reflectionClass = new \ReflectionClass($class);
  
          return $reflectionClass->newInstance($this->serializer, $this->optionsResolver);
      }
docs: Creates a block manager object
  
  @param $action
  @return null|\RedKiteCms\Content\BlockManager\BlockManager