public override IValue Evaluate()
{
var left = _left.Evaluate();
var right = _right.Evaluate();
if (left == null || right == null)
{
return null;
}
var leftValue = left.AsDecimal;
var rightValue = right.AsDecimal;
return new DecimalValue((decimal)Math.Pow(Convert.ToDouble(leftValue), Convert.ToDouble(rightValue)));
}
}