code: func dispatchLabel(d dispatchRequest, c *instructions.LabelCommand) error {
  	if d.state.runConfig.Labels == nil {
  		d.state.runConfig.Labels = make(map[string]string)
  	}
  	commitStr := "LABEL"
  	for _, v := range c.Labels {
  		d.state.runConfig.Labels[v.Key] = v.Value
  		commitStr += " " + v.String()
  	}
  	return d.builder.commit(d.state, commitStr)
  }
docs: // LABEL some json data describing the image
  //
  // Sets the Label variable foo to bar,
  //