rb_hash_dup      1106 eval.c         	    CREF_REFINEMENTS_SET(cref, rb_hash_dup(CREF_REFINEMENTS(cref)));
rb_hash_dup       511 include/ruby/intern.h VALUE rb_hash_dup(VALUE);
rb_hash_dup      9934 io.c               else opt = rb_hash_dup(opt);
rb_hash_dup       148 vm.c           	CREF_REFINEMENTS_SET(new_cref, rb_hash_dup(CREF_REFINEMENTS(cref)));
rb_hash_dup       463 vm_args.c          locals[0] = NIL_P(keyword_hash) ? rb_hash_new() : rb_hash_dup(keyword_hash);