EllisLab/CodeIgniter — pull request #1934 by francimedia (2012-10-26 19:26:06+00:00)
Title: fixed error: loading custom cache driver

Failed to add subclass prefixed based custom cache driver
(example: application/libraries/Cache/drivers/MY_Cache_file.php)

Error message:
"An Error Was Encountered
Unable to load the requested class: Cache"

caused by adding a custom Cache class (/application/libraries/Cache/MY_Cache.php) and loading it using $this->load->driver('cache');