add(node, confidence) {
    const id = getId(node);
    const list = Lists.get(this);
    if (list[id]) {
      if (confidence === 0 || list[id].confidence === 0) {
        list[id].confidence = 0;
      } else {
        list[id].confidence = Math.max(list[id].confidence, confidence);
      }
      return list[id];
    }
    list[id] = {
      node,
      confidence,
    };
    return list[id];
  }
Add a node to the components list, or update it if it's already in the list

@param {ASTNode} node The AST node being added.
@param {number} confidence Confidence in the component detection (0=banned, 1=maybe, 2=yes)
@returns {Object} Added component object