func (sk *SpecialKeyRing) IsValidKID(kid keybase1.KID) bool {
	val, found := sk.validKIDs[kid]
	return val && found
}
IsValidKID returns if this KID is valid (blessed) according to this Keyring
package libkb
import (
	keybase1 "github.com/keybase/client/go/protocol"
)
type SpecialKeyRing struct {
	Contextified
	keys map[keybase1.KID]GenericKey
	validKIDs map[keybase1.KID]bool
}
func NewSpecialKeyRing(v []keybase1.KID, g *GlobalContext) *SpecialKeyRing {
	ret := &SpecialKeyRing{
		keys:         make(map[keybase1.KID]GenericKey),
		validKIDs:    make(map[keybase1.KID]bool),
		Contextified: NewContextified(g),
	}
	for _, kid := range v {
		if key, _ := ImportKeypairFromKID(kid); key != nil {
			ret.keys[kid] = key
		}
		ret.validKIDs[kid] = true
	}
	return ret
}