public void Grab_UnresolvedRuleRef_ThrowsException()
        {
            var ruleRef = new RuleRef <string>();
            var index   = new TokenStreamIndex(new TokenStream(StaticLexer.FromWords()), 0);

            ruleRef.Invoking(r => index.OperationsMock().Evaluate(r)).Should().Throw <InvalidOperationException>();
        }
        public void Clone_UnresolvedRuleRef_ThrowsException()
        {
            var ruleRef = new RuleRef <string>();

            ruleRef.Invoking(r => r.CloneRule()).Should().Throw <InvalidOperationException>();
        }