code: function Strategy(verify) {
  	if (!verify) {
  		throw new TypeError('CustomStrategy requires a verify callback');
  	}
  	passport.Strategy.call(this);
  	this.name = 'custom';
  	this._verify = verify;
  }
docs: `Strategy` constructor.
  
  The custom authentication strategy authenticates requests based on a function callback.
  Applications must supply a `verify` callback which executes custom authentication logic, and then calls the `done` callback supplying a `user`, which should be set to `false` if the credentials are not valid. If an exception occured, `err` should be set.
  
  Examples:
  passport.use(new CustomStrategy(
  function(req, done) {
  User.findOne({
  username: req.body.username
  }, function (err, user) {
  done(err, user);
  });
  }
  ));
  
  @param {Function} verify Verifies the user.
  @api public