code: function pruneIds(form) {
    var testForm = _.clone(form);
    testForm.pages = _.map(testForm.pages, function(page) {
      page.fields = _.map(page.fields, function(field) {
        return _.omit(field, '_id');
      });
  
      return _.omit(page, '_id');
    });
  
    return _.omit(testForm, '_id');
  }
docs: Removing All underscore ids