func (t *Taint) ToString() string {
	if len(t.Value) == 0 {
		return fmt.Sprintf("%v:%v", t.Key, t.Effect)
	}
	return fmt.Sprintf("%v=%v:%v", t.Key, t.Value, t.Effect)
}
taint.ToString() converts taint struct to string in format key=value:effect or key:effect.
package v1
import "fmt"
func (t *Taint) MatchTaint(taintToMatch *Taint) bool {
	return t.Key == taintToMatch.Key && t.Effect == taintToMatch.Effect
}