How to initialize rule expression class

Question

I am working on rules engine using expressions... wanting to implement expressions for and/or for composite rules... using the following stackoverflow thread as a reference: How to implement a rule engine?

I am lost as to how do I initialize a rule class with constructor overloads especially the constructor with 3 parameters... I was hoping any one of the experts here help me with this...

public class RuleExpression {
    public NodeOperator NodeOperator { get; set; }
    public List<RuleExpression> Expressions { get; set; }
    public Rule Rule { get; set; }

    public RuleExpression()
    {

    }
    public RuleExpression(Rule rule)
    {
        NodeOperator = NodeOperator.Leaf;
        Rule = rule;
    }

    public RuleExpression(NodeOperator nodeOperator, List<RuleExpression> expressions, Rule rule)
    {
        this.NodeOperator = nodeOperator;
        this.Expressions = expressions;
        this.Rule = rule;
    }
}


public enum NodeOperator
{
    And,
    Or,
    Leaf
}

Appreciate your help...