+/** This class stores the extra data needed by this plugin about a given host
+ *
+ * It is stored as an extension of s4u::Host. Such extensions are retrieved by type as follows:
+ *
+ * @verbatim
+ * simgrid::s4u::Host* this_host = ???;
+ * this_extension = host->extension<HostLoad>();
+ * @endverbatim
+ *
+ * If no extension of that type was ever attached to the inspected object, the ``extension<X>()`` template returns
+ * nullptr.
+ *
+ * Please refer to the implementation of ``sg_host_load_plugin_init()`` to see the extension objects are attached to
+ * hosts at initialization time.
+ */