private void addSystemCredentialsToProto() {
   maybeInitBuilder();
   builder.clearSystemCredentialsForApps();
   for (Map.Entry<ApplicationId, ByteBuffer> entry : systemCredentials.entrySet()) {
     builder.addSystemCredentialsForApps(
         SystemCredentialsForAppsProto.newBuilder()
             .setAppId(convertToProtoFormat(entry.getKey()))
             .setCredentialsForApp(ProtoUtils.convertToProtoFormat(entry.getValue().duplicate())));
   }
 }
 private ExecutionTypeProto convertToProtoFormat(ExecutionType executionType) {
   return ProtoUtils.convertToProtoFormat(executionType);
 }
 private ContainerTypeProto convertToProtoFormat(ContainerType containerType) {
   return ProtoUtils.convertToProtoFormat(containerType);
 }