getConfig function is for retrieving the current configuration object or subscribing to configuration updates. When called with no parameters, the entire config object is returned. When called with a string parameter, a single configuration property matching that parameter is returned.
getConfig function also contains a ‘subscribe’ ability that adds a callback function to a set of listeners that are invoked whenever
setConfig is called. The subscribed function will be passed the options object that was used in the
setConfig call. Individual topics can be subscribed to by passing a string as the first parameter and a callback function as the second. For example: