SVG.Use = SVG.invent({
  // Initialize node
  create: 'use',

  // Inherit from
  inherit: SVG.Shape,

  // Add class methods
  extend: {
    // Use element as a reference
    element: function (element, file) {
      // Set lined element
      return this.attr('href', (file || '') + '#' + element, SVG.xlink)
    }
  },

  // Add parent method
  construct: {
    // Create a use element
    use: function (element, file) {
      return this.put(new SVG.Use()).element(element, file)
    }
  }
})