docs: function isVacuousFunction(node) {
    return node.TYPE === 'Call' && node.expression.TYPE === 'Dot' &&
      node.expression.property === 'call' && node.expression.expression.TYPE === 'Function' &&
      node.expression.expression.argnames.length == 0 && node.args.length === 1 &&
      node.args[0].TYPE === 'This';
  }