code: function uuid(version) {
      var v = (version) ? version : '';
  
      // verify its a valid string
      this.assert(
        (typeof this._obj === 'string' || this._obj instanceof String),
        'expected #{this} to be of type #{exp} but got #{act}',
        'expected #{this} to not be of type #{exp}',
        'string',
        typeof(this._obj)
      );
  
      // assert it is a valid uuid
      var regex = getRegEx(v);
      this.assert(
        regex.test(this._obj),
        'expected #{this} to be a valid UUID ' + v,
        'expected #{this} to not be a UUID ' + v
      );    
    }
docs: Validates a uuid
  @param  {String} version