code: @Override
    public Map<byte[], byte[]> hgetAll(final byte[] key) {
      checkIsInMultiOrPipeline();
      client.hgetAll(key);
      final List<byte[]> flatHash = client.getBinaryMultiBulkReply();
      final Map<byte[], byte[]> hash = new JedisByteHashMap();
      final Iterator<byte[]> iterator = flatHash.iterator();
      while (iterator.hasNext()) {
        hash.put(iterator.next(), iterator.next());
      }
  
      return hash;
    }
docs: Return all the fields and associated values in a hash.
  <p>
  <b>Time complexity:</b> O(N), where N is the total number of entries
  @param key
  @return All the fields and values contained into a hash.