+/**
+ * Testbed has provided us with the configuration to access one
+ * of the peers and it is time to do "some" connect operation to
+ * "some" subsystem of the peer. For this example, we connect
+ * to the DHT subsystem. Testbed doesn't know which subsystem,
+ * so we need these adapters to do the actual connecting (and
+ * possibly pass additional options to the subsystem connect
+ * function, such as the "ht_len" argument for the DHT).
+ *
+ * @param cls closure
+ * @param cfg peer configuration (here: peer[0]
+ * @return NULL on error, otherwise some handle to access the
+ * subsystem
+ */