func DoesntContain(usrValue interface{}, validValues []interface{}) (bool, error) {
	for _, v := range validValues {
		ok, err := contains(v, usrValue)
		if err != nil {
			return false, err
		}
		if ok {
			return false, nil
		}
	}
	return true, nil
}
DoesntContain operator will check if the value from the user context doesn't contain
any of the configured values on the flag.
package operator
import (
	"errors"
	"strings"
)
func Contains(usrValue interface{}, validValues []interface{}) (bool, error) {
	for _, v := range validValues {
		ok, err := contains(v, usrValue)
		if err != nil {
			return false, err
		}
		if ok {
			return true, nil
		}
	}
	return false, nil
}