angular defaults from https://glebbahmutov.com/blog/angular-nuggets/

angular defaults

function defaults(_defaults, opts) {
  opts = opts || {};
  return angular.extend(angular.copy(_defaults), opts);
}
function foo(options) {
    var _defaults = {
        bar: 'baz'
    };
    options = defaults(_defaults, options);
}
foo({ bar: 'my bar' }); // options is { bar: 'my bar' }
foo(); // options is { bar: 'baz' }