docs: function Rug( graph ) {
  
  	// INSTANCE ATTRIBUTES //
  
  	this._parent = graph;
  	this._root = undefined;
  	this._children = {};
  	this._config = {
  		"type": "rug",
  		"size": 6,
  		"labels": []
  	};
  
  	// DATA //
  
  	this._data = graph._data;
  
  	// TRANSFORMS //
  
  	this._transforms = {
  		'x': function X( d ) {
  			return graph._xScale( d[ 0 ] );
  		},
  		'y': function Y( d ) {
  			return d[ 1 ];
  		}
  	};
  
  	// GENERATOR //
  
  	this._path = this.path()
  		.x( this._transforms.x )
  		.y( this._transforms.y );
  
  	// REGISTER //
  	if ( graph._config.hasOwnProperty( 'marks' ) ) {
  		graph._config.marks.push( this._config );
  	} else {
  		graph._config.marks = [ this._config ];
  	}
  	if ( graph._children.hasOwnProperty( 'marks' ) ) {
  		graph._children.marks.push( this );
  	} else {
  		graph._children.marks = [ this ];
  	}
  
  	return this;
  }