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.trans.x : this.transform('x', x) } // Move over y-axis , y: function(y) { return y == null ? this.trans.y : this.transform('y', y) } // Move by center over x-axis , cx: function(x) { return x == null ? this.bbox().cx : this.x(x - this.bbox().width / 2) } // Move by center over y-axis , cy: function(y) { return y == null ? this.bbox().cy : this.y(y - this.bbox().height / 2) } } // Add parent method , construct: { // Create a group element group: function() { return this.put(new SVG.G) } } })