RHASH_ITER_LEV   1049 include/ruby/ruby.h #define RHASH_ITER_LEV(h) rb_hash_iter_lev(h)
RHASH_ITER_LEV    566 internal.h     #undef RHASH_ITER_LEV
RHASH_ITER_LEV    569 internal.h     #define RHASH_ITER_LEV(h) (RHASH(h)->iter_lev)