code: public function get($key)
      {
          if (array_key_exists($key, $this->messages)) {
              return !empty($this->messages[$key]) ? $this->messages[$key] : null;
          }
  
          return null;
      }
docs: Get all of the messages from a given key.
  Returns null if the given key is empty, or
  if it doesn't exist.
  
  @param  string $key
  @return array|null