code: private int insertKey(final byte[] key) {
      final long[] hash = MurmurHash3.hash(key, SEED);
      int entryIndex = getIndex(hash[0], tableEntries_);
      final int loopIndex = entryIndex;
      do {
        if (isBitClear(stateArr_, entryIndex)) {
          System.arraycopy(key, 0, keysArr_, entryIndex * keySizeBytes_, keySizeBytes_);
          setBit(stateArr_, entryIndex);
          numActiveKeys_++;
          return entryIndex;
        }
        entryIndex = (entryIndex + getStride(hash[1], tableEntries_)) % tableEntries_;
      } while (entryIndex != loopIndex);
      throw new SketchesArgumentException("Key not found and no empty slots!");
    }
docs: for internal use during resize, so no resize check here