vm_define_method 1723 vm.c           	vm_define_method(GET_THREAD(), cbase, SYM2ID(sym), iseqval, 0, rb_vm_cref());
vm_define_method 1732 vm.c           	vm_define_method(GET_THREAD(), cbase, SYM2ID(sym), iseqval, 1, rb_vm_cref());