Function multiple

test/mocha.js:4139–4145

(err)

  // called multiple times
  function multiple(err) {
    if (emitted) {
      return;
    }
    emitted = true;
    self.emit('error', err || new Error('done() called multiple times; stacktrace may be inaccurate'));
  }

  // finished
  function done(err) {