code: function (revert) {
  		var clone = this.renderToClone,
  			container = this.container;
  		
  		// Destroy the clone and bring the container back to the real renderTo div
  		if (revert) {
  			if (clone) {
  				this.renderTo.appendChild(container);
  				discardElement(clone);
  				delete this.renderToClone;
  			}
  		
  		// Set up the clone
  		} else {
  			if (container && container.parentNode === this.renderTo) {
  				this.renderTo.removeChild(container); // do not clone this
  			}
  			this.renderToClone = clone = this.renderTo.cloneNode(0);
  			css(clone, {
  				position: ABSOLUTE,
  				top: '-9999px',
  				display: 'block' // #833
  			});
  			doc.body.appendChild(clone);
  			if (container) {
  				clone.appendChild(container);
  			}
  		}
  	}
docs: Create a clone of the chart's renderTo div and place it outside the viewport to allow
  size computation on chart.render and chart.redraw