*************/
simgrid::xbt::signal<void(VirtualMachineImpl*)> VirtualMachineImpl::on_creation;
simgrid::xbt::signal<void(VirtualMachineImpl*)> VirtualMachineImpl::on_destruction;
-simgrid::xbt::signal<void(VirtualMachineImpl*)> VirtualMachineImpl::on_state_change;
+
/*********
* Model *
*********/