rb_fiber_yield    977 cont.c             return rb_fiber_yield(argc, argv);
rb_fiber_yield    473 enumerator.c       rb_fiber_yield(argc, argv);
rb_fiber_yield    485 enumerator.c       return rb_fiber_yield(1, &nil);
rb_fiber_yield    176 include/ruby/intern.h VALUE rb_fiber_yield(int argc, VALUE *args);