+/// Set the poll callback.
+/** This functions sets the callback that is called whenever data can be sent to another node.
+ * The callback is run in MeshLink's own thread.
+ * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
+ * to pass data to or from the application's thread.
+ * The callback should also not block itself and return as quickly as possible.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ * @param cb A pointer to the function which will be called when data can be sent to another node.
+ * If a NULL pointer is given, the callback will be disabled.
+ */
+extern void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_poll_cb_t cb);
+