rb_io_s_open     6585 io.c               return rb_io_s_open(argc, argv, rb_cFile);
rb_io_s_open     12243 io.c               rb_define_singleton_method(rb_cFile, "open",  rb_io_s_open, -1);
rb_io_s_open     12248 io.c               rb_define_singleton_method(rb_cIO, "open",  rb_io_s_open, -1);