code: func ReleasePorts(portMapper *portmapper.PortMapper, bindings []types.PortBinding) error {
  	var errorBuf bytes.Buffer
  
  	// Attempt to release all port bindings, do not stop on failure
  	for _, m := range bindings {
  		if err := releasePort(portMapper, m); err != nil {
  			errorBuf.WriteString(fmt.Sprintf("\ncould not release %v because of %v", m, err))
  		}
  	}
  
  	if errorBuf.Len() != 0 {
  		return errors.New(errorBuf.String())
  	}
  	return nil
  }
docs: // ReleasePorts releases ports specified in bindings from the portMapper