code: public Deferred<byte[]> resolveTagkName(final TSDB tsdb) {
      class ResolvedCB implements Callback<byte[], byte[]> {
        @Override
        public byte[] call(final byte[] uid) throws Exception {
          tagk_bytes = uid;
          return uid;
        }
      }
      
      return tsdb.getUIDAsync(UniqueIdType.TAGK, tagk)
          .addCallback(new ResolvedCB());
    }
docs: Asynchronously resolves the tagk name to it's UID. On a successful lookup
  the {@link tagk_bytes} will be set.
  @param tsdb The TSDB to use for the lookup
  @return A deferred to let the caller know that the lookup was completed.
  The value will be the tag UID (unless it's an exception of course)