A func operand.
Inheritance: OperandBase
        public void IsTrue(Func<object, bool> func)
        {
            var operand = new FuncOperand((o) =>
            {
                if (o == null)
                {
                    return false;
                }

                return func(o);
            });

            operand.Operator = new EqualsOperator(operand, new FixedValueOperand(true));

            LeftOperands.Add(operand);
        }
        public OperandBase Func(Func<object, object> func)
        {
            var operand = new FuncOperand(func);
            LeftOperands.Add(operand);

            return operand;
        }