code: func (p *Process) ping() error {
  	// Send request.
  	resp, err := http.Get(p.URL() + "/ping")
  	if err != nil {
  		return err
  	}
  	resp.Body.Close()
  
  	// Verify successful status code.
  	if resp.StatusCode != http.StatusOK {
  		return fmt.Errorf("unexpected status: %d", resp.StatusCode)
  	}
  	return nil
  }
docs: // ping checks the process to see if it is up.