code: function updateFiles(anIncludeList, anExcludeList) {
  		if (!arraysDeepEqual(anIncludeList, includeList) ||
  			!arraysDeepEqual(anExcludeList, excludeList)) { // some change
  			includeList = anIncludeList
  			excludeList = anExcludeList
  			createWatchers()
  		}
  		return watcherCount
  	}
docs: /*
  includeList: array of string: absolute path to file or folder
  excludeList: array of string: items that starts with any of these are excluded
  return value: number of files being watched