env_has_key      2689 hash.c             rb_define_singleton_method(envtbl,"include?", env_has_key, 1);
env_has_key      2690 hash.c             rb_define_singleton_method(envtbl,"member?", env_has_key, 1);
env_has_key      2691 hash.c             rb_define_singleton_method(envtbl,"has_key?", env_has_key, 1);
env_has_key      2693 hash.c             rb_define_singleton_method(envtbl,"key?", env_has_key, 1);