func Example_args() {
	var (
		root = cmd.New()
		args = root.Args("[args...]", "positional arguments for command line")
	)
	root.ParseArgs("cmd", "v1", "v2", "v3")
	fmt.Println(*args)
}
In the cmd package, positional arguments should be explicitly defined. They are defined using the
`Args` or `ArgsVar` methods.
package cmd_test
import (
	"fmt"
	"github.com/posener/cmd"
)