pub unsafe extern "C" fn OPENSSL_sk_deep_copy(
    sk: *const OPENSSL_STACK,
    call_copy_func: OPENSSL_sk_call_copy_func,
    copy_func: OPENSSL_sk_copy_func,
    call_free_func: OPENSSL_sk_call_free_func,
    free_func: OPENSSL_sk_free_func
) -> *mut OPENSSL_STACK