export default abstract class ExpressionNode {
    left: ExpressionNode;
    right: ExpressionNode;
    parent: ExpressionNode;
    constructor(left: ExpressionNode, right: ExpressionNode);
    abstract serialize(): any;
    traverse<T, U extends ExpressionNode>(getValue: (node: U) => T, valueCondition: (node: U) => boolean, traverseCondition?: (node: ExpressionNode) => boolean): Array<T>;
    find<T, U extends ExpressionNode>(getValue: (node: U) => T, valueCondition: (node: U) => boolean): T | null;
    assignParents(): ExpressionNode;
    private recursiveTraverse;
    private recursiveFind;
    private recursiveAssignParents;
}