 
 	# ## flushAll
 	#
-	# flush the hole data and reset the stats
+	# flush the whole data and reset the stats
 	#
 	# **Example:**
 	#


	# ## ttl
	#
	# reset or redefine the ttl of a key. `ttl` = 0 means inifite lifetime.
	# If `ttl` is not passed the default ttl is used.
	# If `ttl` < 0 the key will be deleted.
	#


	# ## _checkData
	#
	# internal housekeeping method.
	# Check all the cached data and delete the invalid values
	_checkData: ( startPeriod = true )=>
		# run the housekeeping method
