signature/policy_config.go
func NewPRSignedByKeyData(keyType sbKeyType, keyData []byte, signedIdentity PolicyReferenceMatch) (PolicyRequirement, error) {
	return newPRSignedByKeyData(keyType, keyData, signedIdentity)
}
func NewPRSignedByKeyData(keyType sbKeyType, keyData []byte, signedIdentity PolicyReferenceMatch) (PolicyRequirement, error) {
	return newPRSignedByKeyData(keyType, keyData, signedIdentity)
}
// NewPRSignedByKeyData returns a new "signedBy" PolicyRequirement using a KeyData