RUBY_EVENT_FIBER_SWITCH 1275 cont.c         	EXEC_EVENT_HOOK(th, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, Qnil);
RUBY_EVENT_FIBER_SWITCH 1465 cont.c             EXEC_EVENT_HOOK(th, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, Qnil);