code: function findNode(children, path, protectedId) {
    var prefix = getProtectedPrefix(protectedId);
    var i = 0;
    var node;
    while ((node = children[i++])) {
      if (node.indexOf(prefix) === 0) {
        return utils.join(path, node);
      }
    }
    return null;
  }
docs: Find znode among children list with given prefix.
  
  @param {Array.<String>} children
  @param {String} path
  @param {String} protectedId
  @returns {String|null}