code: func (c *cmd) makeRExecSpec() ([]byte, error) {
  	spec := &rExecSpec{
  		Command: c.conf.cmd,
  		Args:    c.conf.args,
  		Script:  c.conf.script,
  		Wait:    c.conf.wait,
  	}
  	return json.Marshal(spec)
  }
docs: // makeRExecSpec creates a serialized job specification
  // that can be uploaded which will be parsed by agents to
  // determine what to do.