public static synchronized DiskCache get(File directory, int maxSize) {
        // TODO calling twice with different arguments makes it return the cache for the same directory, it's public!
        if (wrapper == null) {
            wrapper = new DiskLruCacheWrapper(directory, maxSize);
        }
        return wrapper;
    }
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