code: function VinylGroup(group) {
    if (!(this instanceof VinylGroup)) {
      return new VinylGroup(group);
    }
  
    if (!group) group = {};
    utils.File.call(this);
  
    is(this, 'VinylGroup');
    this.group = group;
  }
docs: Create an instance of `VinylGroup`. Pass in a group from [group-array][] to store.
  
  ```js
  var files = [ ... ]; // array of vinyl files
  var group = groupArray(files, 'data.tags');
  var vinylGroup = new VinylGroup(group);
  
  console.log(vinylGroup.group === group);
  //=> true
  
  console.log(vinylGroup);
  //=> <VinylGroup ["foo (3)", "bar (3)"]>
  ```
  @param {Object} `group` A group object created by passing an array of [vinyl][] file into [group-array][].
  @api public