reducerHash function is so central to the
rudimentary aspect of reduction, it is a common practice to extend
this function, providing a common spot to emit valuable logging
Not only are these probes centrally located in a common spot, but they can easily correlate logging levels to state changes, providing a means to filter logs at a high level with minimal output.
As an example: filter the logs to named reducers that actually change the state.
TODO: build up an example of this.