code: public function setUsername($username = '')
      {
          $this->username = $username;
          $this->logger->debug(__FUNCTION__, 'setUsername: ', $this->username);
  
          return $this;
      }
docs: Function setUsername
  
  @author: 713uk13m <dev@nguyenanhung.com>
  @time  : 11/11/18 13:52
  
  @param string $username
  
  @return $this|mixed