args.go
func (a *Args) GetBool(key string) bool {
	switch b2s(a.Peek(key)) {
	// Support the same true cases as strconv.ParseBool
	// See: https://github.com/golang/go/blob/4e1b11e2c9bdb0ddea1141eed487be1a626ff5be/src/strconv/atob.go#L12
	// and Y and Yes versions.
	case "1", "t", "T", "true", "TRUE", "True", "y", "yes", "Y", "YES", "Yes":
		return true
	default:
		return false
	}
}
func (a *Args) GetBool(key string) bool {
	switch b2s(a.Peek(key)) {
	// Support the same true cases as strconv.ParseBool
	// See: https://github.com/golang/go/blob/4e1b11e2c9bdb0ddea1141eed487be1a626ff5be/src/strconv/atob.go#L12
	// and Y and Yes versions.
	case "1", "t", "T", "true", "TRUE", "True", "y", "yes", "Y", "YES", "Yes":
		return true
	default:
		return false
	}
}
// GetBool returns boolean value for the given key.
//
// true is returned for "1", "t", "T", "true", "TRUE", "True", "y", "yes", "Y", "YES", "Yes",
// otherwise false is returned.