original_string: public function setSubMerchant(string $mchId, string $appId = null)
      {
          $this['config']->set('sub_mch_id', $mchId);
          $this['config']->set('sub_appid', $appId);
  
          return $this;
      }
code: public function setSubMerchant(string $mchId, string $appId = null)
      {
          $this['config']->set('sub_mch_id', $mchId);
          $this['config']->set('sub_appid', $appId);
  
          return $this;
      }
code_tokens: public function setSubMerchant ( string $ mchId , string $ appId = null ) { $ this [ 'config' ] -> set ( 'sub_mch_id' , $ mchId ) ; $ this [ 'config' ] -> set ( 'sub_appid' , $ appId ) ; return $ this ; }
docstring: Set sub-merchant.
  
  @param string      $mchId
  @param string|null $appId
  
  @return $this
docstring_tokens: Set sub - merchant .