code: func NewStaticSigningKeyRepositoryFromStringSlice(idkeys []string) *StaticSigningKeyRepository {
  	keys := make(map[string]string, len(idkeys))
  	for _, idkey := range idkeys {
  		idAndKey := strings.Split(idkey, ":")
  		if len(idAndKey) != 2 {
  			panic("Bad request signing keys string!")
  		}
  		keys[idAndKey[0]] = idAndKey[1]
  	}
  	return NewStaticSigningKeyRepository(keys)
  }
docs: // NewStaticSigningKeyRepositoryFromStringSlice creates a SigningKeyRepository from a string slice
  // in form of []string{"keyId:keyValue"}, which can be used with StringSlice from https://github.com/urfave/cli.