If you're using `with-spec`, this test class and the test names below won't provide very useful output. Would prefer something more descriptive (either through new class/method names or docstrings). As it is now, we'd see spec output like this:

	Decorator Test Case
	- property caching
	- clearing cache for single property
	- clearing cache for all properties
	etc...
	
The spec output should read like actual specs. For example:

	@cached_property
	- returns the calculated value
	- does not recalculate the value on subsequent calls
	
	clear_cached_properties_for(object, method_name)
	- clears the calculated value
	- does not affect other cached properties on the object
	
	clear-cached_properties_for(object)
	- clears all cached properties on the object