private synchronized void resetDiskCache() {
        diskLruCache = null;
    }
Get a DiskCache in the given directory and size. If a disk cache has alread been created with
a different directory and/or size, it will be returned instead and the new arguments
will be ignored.

@param directory The directory for the disk cache
@param maxSize The max size for the disk cache
@return The new disk cache with the given arguments, or the current cache if one already exists
core/src/main/java/com/bumptech/glide/load/engine/cache/DiskLruCacheWrapper.java