code: @Override
    public Double hincrByFloat(final byte[] key, final byte[] field, final double value) {
      checkIsInMultiOrPipeline();
      client.hincrByFloat(key, field, value);
      final String dval = client.getBulkReply();
      return (dval != null ? new Double(dval) : null);
    }
docs: Increment the number stored at field in the hash at key by a double precision floating point
  value. If key does not exist, a new key holding a hash is created. If field does not exist or
  holds a string, the value is set to 0 before applying the operation. Since the value argument
  is signed you can use this command to perform both increments and decrements.
  <p>
  The range of values supported by HINCRBYFLOAT is limited to double precision floating point
  values.
  <p>
  <b>Time complexity:</b> O(1)
  @param key
  @param field
  @param value
  @return Double precision floating point reply The new value at field after the increment
  operation.