The code base has a few puts as means of conveying what is happening. However, these will always output to $stdout. This is not always desired, so the library should instead log these print statements to QueueBus.logger.debug { "output" }. Since this library is high throughput, use a proc to avoid creating the strings if they are interpolated (as the block is not executed). There is no need to use the block syntax if the strings are frozen literals.