constructor(root, options) {
    super(root)
    this.filename = options.filename;
    this.paths = options.paths || [];
    this.paths.push(dirname(options.filename || '.'));
    this.options = options;
    this.functions = {};
    this.deps = [];
  }
Initialize a new `DepsResolver` with the given `root` Node
and the `options`.

@param {Node} root
@param {Object} options
@api private