@Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        OriginalKey that = (OriginalKey) o;

        if (!id.equals(that.id)) {
            return false;
        }
        if (!signature.equals(that.signature)) {
            return false;
        }

        return true;
    }
A class for keeping track of the cache key of the original data + any requested signature.
core/src/main/java/com/bumptech/glide/load/engine/OriginalKey.java