lib/functional.js
function () {
    return new Promise(function (resolve, reject) {
      portfinder.getPort(function (error, port) {
        if (error) {
          reject(error);
        } else {
          resolve(port);
        }
      });
    });
  }
function () {
    return new Promise(function (resolve, reject) {
      portfinder.getPort(function (error, port) {
        if (error) {
          reject(error);
        } else {
          resolve(port);
        }
      });
    });
  }
Functional._getOpenPort() -> Object