code: public function isChanged()
      {
          if ($this->changed) {
              return true;
          }
  
          if (self::isLegacyMode()) {
              foreach ($this as $token) {
                  if ($token->isChanged()) {
                      return true;
                  }
              }
          }
  
          return false;
      }
docs: Check if collection was change: collection itself (like insert new tokens) or any of collection's elements.
  
  @return bool