docs: function (methodInvocation, options) {
    for (var i = 0; i < loginHandlers.length; ++i) {
      var handler = loginHandlers[i];
  
      var result = tryLoginMethod(
        handler.name,
        function () {
          return handler.handler.call(methodInvocation, options);
        }
      );
  
      if (result)
        return result;
      else if (result !== undefined)
        throw new Meteor.Error(400, "A login handler should return a result or undefined");
    }
  
    return {
      type: null,
      error: new Meteor.Error(400, "Unrecognized options for login request")
    };
  }