code: func New(buffer, backing sorted.KeyValue, maxBufferBytes int64) *KeyValue {
  	return &KeyValue{
  		buf:       buffer,
  		back:      backing,
  		maxBuffer: maxBufferBytes,
  	}
  }
docs: // New returnes a sorted.KeyValue implementation that adds a Flush
  // method to flush the buffer to the backing storage. A flush will
  // also be performed when maxBufferBytes are reached. If
  // maxBufferBytes <= 0, no automatic flushing is performed.