protected internal virtual object EvaluateFeelSimpleUnaryTests(DmnDecisionTableInputImpl input,
                                                                       DmnExpressionImpl condition, IVariableContext variableContext)
        {
            //return new NotImplementedException();
            var expressionText = condition.Expression;

            if (!ReferenceEquals(expressionText, null))
            {
                return(feelEngine.EvaluateSimpleUnaryTests(expressionText, input.InputVariable, variableContext));
            }
            return(null);
        }