Requests that the given string is added to the image cache. You should only do this rarely, but
if you have a string that you know will be used over and over again, adding it to a cache can
improve things (assuming the implementation actually has a cache; it is also valid for an implementation
to implement this as a do-nothing method).
Requests that the given string is added to the image cache. You should only do this rarely, but if you have a string that you know will be used over and over again, adding it to a cache can improve things (assuming the implementation actually has a cache; it is also valid for an implementation to implement this as a do-nothing method).