code: public function update($account, $nickname)
      {
          $params = [
                     'kf_account' => $account,
                     'nickname' => $nickname,
                    ];
  
          return $this->parseJSON('json', [self::API_UPDATE, $params]);
      }
docs: Update a staff.
  
  @param string $account
  @param string $nickname
  
  @return \EasyWeChat\Support\Collection