[1.8.x] Fixed #25727 -- Added a doc link to cached_property.

It's common to have to call a class instances's method more than once. If

that function is expensive, then doing so can be wasteful.

Using the ``@cached_property`` decorator saves the value returned by a

property; the next time the function is called on that instance, it will return

the saved value rather than re-computing it. Note that this only works on

methods that take ``self`` as their only argument and that it changes the

method to a property.

Using the :class:`~django.utils.functional.cached_property` decorator saves the

value returned by a property; the next time the function is called on that

instance, it will return the saved value rather than re-computing it. Note that

this only works on methods that take ``self`` as their only argument and that

it changes the method to a property.

Certain Django components also have their own caching functionality; these are

discussed below in the sections related to those components.