code: function () {
        if (doc.groupId.length < 1) {
          return;
        }
        // exception for @incowia -users
        if (doc.author.email.indexOf('@incowia') &&
          (doc.groupId === 'cubx' || doc.groupId.indexOf('cubx.', 0) === 0)) {
          return;
        }
        var authorMailDomainArray = doc.author.email.replace(/.*@/, '').split('.');
        var expectedGroupId = authorMailDomainArray.reverse().join('.');
        if (doc.groupId.indexOf(expectedGroupId, 0) !== 0) {
          errors.push(
            'RuleViolation identified: Non-empty \'groupId\' must start with the (reversed) author ' +
            'email-domain to avoid misuse of groupId\'s: ' +
            '[(groupId) \'' + doc.groupId + '\' != ' + expectedGroupId + ' (reversed author email-domain)].');
        }
      }
docs: Rule 1: If there is a groupId, it is expected to start with the authors email-domain. except for @incowia -users, which are allowed to be author of packages of cubx.*-webpackages