SVG.G = SVG.invent({
  // Initialize node
  create: 'g'

  // Inherit from
, inherit: SVG.Container

  // Add class methods
, extend: {
    // Move over x-axis
    x: function(x) {
      return x == null ? this.transform('x') : this.transform({ x: x - this.x() }, true)
    }
    // Move over y-axis
  , y: function(y) {
      return y == null ? this.transform('y') : this.transform({ y: y - this.y() }, true)
    }
    // Move by center over x-axis
  , cx: function(x) {
      return x == null ? this.gbox().cx : this.x(x - this.gbox().width / 2)
    }
    // Move by center over y-axis
  , cy: function(y) {
      return y == null ? this.gbox().cy : this.y(y - this.gbox().height / 2)
    }
  , gbox: function() {

      var bbox  = this.bbox()
        , trans = this.transform()

      bbox.x  += trans.x
      bbox.x2 += trans.x
      bbox.cx += trans.x

      bbox.y  += trans.y
      bbox.y2 += trans.y
      bbox.cy += trans.y

      return bbox
    }
  }

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