docs: public Entry<Bits, T> decode(final Bits data) {
      if (null == data) {
        throw new IllegalArgumentException();
      }
      Entry<Bits, T> entry = this.forwardIndex.floorEntry(data);
      // TestUtil.openJson(new JSONObject(forwardIndex));
      if (entry != null && !data.startsWith(entry.getKey())) {
        entry = null;
      }
      // assert(null != entry || verifyIndexes());
      return entry;
    }