code: function addRow(layoutConfig, layoutData, row) {
  
  	layoutData._rows.push(row);
  	layoutData._layoutItems = layoutData._layoutItems.concat(row.getItems());
  
  	// Increment the container height
  	layoutData._containerHeight += row.height + layoutConfig.boxSpacing.vertical;
  
  	return row.items;
  }
docs: Add a completed row to the layout.
  Note: the row must have already been completed.
  
  @method addRow
  @param layoutConfig {Object} The layout configuration
  @param layoutData {Object} The current state of the layout
  @param row {Row} The row to add.
  @return {Array} Each item added to the row.