code: protected long writeValue(File file, ValueData value) throws IOException
     {
        if (value.isByteArray())
        {
           return writeByteArrayValue(file, value);
        }
        else
        {
           return writeStreamedValue(file, value);
        }
     }
docs: Write value to a file.
  
  @param file
  File
  @param value
  ValueData
  @return size of wrote content
  @throws IOException
  if error occurs