wnd->set_title("NetVis");
wnd->signal_close.connect(sigc::bind(sigc::mem_fun(this, &NetVis::exit), 0));
wnd->signal_key_press.connect(sigc::mem_fun(this, &NetVis::key_press));
wnd->set_title("NetVis");
wnd->signal_close.connect(sigc::bind(sigc::mem_fun(this, &NetVis::exit), 0));
wnd->signal_key_press.connect(sigc::mem_fun(this, &NetVis::key_press));