id_core_undef_method 5749 compile.c      	ADD_SEND(ret, line, id_core_undef_method, INT2FIX(2));
id_core_undef_method  122 id.c               REGISTER_SYMID(id_core_undef_method, "core#undef_method");
id_core_undef_method 2685 vm.c               rb_define_method_id(klass, id_core_undef_method, m_core_undef_method, 2);