How to update code of a custom node in node material system?

Questions
1

I created a custom node like below， It means Blending some textures to diffuse color, and running at postprocessing. the method .textures can update textures of the node. After size of textures is changed, .setup is supposed to rerun to update the code of node. But I found .steup only run once and never update again. How can I trigger the method .setup of a node? I’ve tried setting .needsUpdate is true or recreate the node, but both of them didn’t work.

class AddTexturesNode extends Node {

    constructor(colorNode, textures) {
        super('vec4');
        this._colorNode = colorNode;
        this._textures = textures || [];
    }

    setup(builder) {

        const addTextureColor = tslFn(([oldColor, map]) => {
            const transformUV = uv();
            let color = oldColor.toVar('finalColor');
            const sampleColor = map.uv(transformUV);
            color.assign(vec4(mix(sampleColor.rgb, color.rgb, sampleColor.a.oneMinus()),
                add(color.a, sampleColor.a)));
            return color;
        });
        const texturesCount = this._textures.length;

        for (let i = 0; i < texturesCount; ++i) {
            this['texture' + i] = texture(this._textures[i]);
        
        }
       
        const addTextures = tslFn(() => {
            let color = this._colorNode;
            if (texturesCount > 0) {
                color = addTextureColor(color, this.texture0);
            }
            if (texturesCount > 1) {
                color = addTextureColor(color, this.texture1);
            }
            return color;
        });
        return addTextures();
    }

    textures(textures) {
        const oldTextureCount = this._textures.length;
        const newTextureCount = textures.length;
        if (this._inited && oldTextureCount === newTextureCount) {
            for (let i = 0; i < newTextureCount; ++i) {
                if (this['texture' + i]) {
                    this['texture' + i].value = textures[i];
                }
            }
        }
        else {
            this.needsUpdate = true;
        }
        this._textures = textures || [];
        return this;
    }
}

export const addTextures = (node, textures, textureInfos) => nodeObject(
    new AddTexturesNode(nodeObject(node).toTexture(), textures, textureInfos));