code: public function getHeaders()
      {
          if (!isset($this->_headers)) {
              $this->_headers = $this->readLine(1);
              if (!$this->_headers) {
                  $this->_headers = [];
              }
          }
  
          return $this->_headers;
      }
docs: Get headers.
  
  @return [[@doctodo return_type:getHeaders]] [[@doctodo return_description:getHeaders]]