code: protected Xdr getCredential() {
          Xdr credentials = new Xdr(_maximumXdrBytes);
          credentials.setOffset(0);
          credentials.putInt((int) (System.currentTimeMillis() / 1000));
          credentials.putString(_host);
          credentials.putInt(_uid);
          credentials.putInt(_gid);
          if (_gids == null) {
              credentials.putInt(0);
          } else {
              credentials.putInt(_gids.length);
              for (int i = 0; i < _gids.length; i++)
                  credentials.putInt(_gids[i]);
          }
          return credentials;
      }
docs: /*
  (non-Javadoc)
  
  @see com.emc.ecs.nfsclient.rpc.CredentialBase#getCredential()