+ * Use PHP serialization to avoid bugs and easily create CAS tokens.
+ * APCu has a memory corruption bug when the serializer is set to 'default'.
+ * See T120267, and upstream bug reports:
+ * - https://github.com/krakjoe/apcu/issues/38
+ * - https://github.com/krakjoe/apcu/issues/35
+ * - https://github.com/krakjoe/apcu/issues/111
+ *