child/child.go
func (c *Child) Command() string {
	list := append([]string{c.command}, c.args...)
	return strings.Join(list, " ")
}
func (c *Child) Command() string {
	list := append([]string{c.command}, c.args...)
	return strings.Join(list, " ")
}
// Command returns the human-formatted command with arguments.