protected Builder withCore(KeyVersionCore kvCore)
throws InvalidProtocolBufferException {
super.withCore(kvCore);
// Extract info from core
AesKeyVersionCore core = kvCore.getExtension(AesKeyVersionCore.extension);
this.matterVector(core.getMatter().toByteArray(), null);
// valueOf()s below can fail if the mode/padding stored is unsupported
this.mode(Mode.valueOf(core.getBlockMode().name()));
this.padding(Padding.valueOf(core.getPadding().name()));
return this;
}