fdbm_fetch        184 ext/dbm/dbm.c      return fdbm_fetch(obj, keystr, Qnil);
fdbm_fetch        193 ext/dbm/dbm.c      valstr = fdbm_fetch(obj, keystr, ifnone);
fdbm_fetch        260 ext/dbm/dbm.c          rb_ary_push(new, fdbm_fetch(obj, argv[i], Qnil));