rb_obj_singleton_methods  162 include/ruby/intern.h VALUE rb_obj_singleton_methods(int, VALUE*, VALUE);
rb_obj_singleton_methods 1726 object.c       	return rb_obj_singleton_methods(argc, argv, obj);
rb_obj_singleton_methods 2537 object.c           rb_define_method(rb_mKernel, "singleton_methods", rb_obj_singleton_methods, -1); /* in class.c */