code: function CommandCenter(app) {
  	this.app = app;
  	this.exposed = false;
  	this.commands = {};
  
  	let ttl;
  
  	if (app.config && app.config.hasOwnProperty('responseCache')) {
  		ttl = app.config.responseCache;
  	} else {
  		ttl = DEFAULT_RESPONSE_CACHE_TTL;
  	}
  
  	this.responseCache = new ResponseCache(app.name, ttl);
  }
docs: CommandCenter implementation