/** * Calculates the count for a set of data. * @since 6.5.0 */Ext.define('Ext.data.summary.Count', { extend: 'Ext.data.summary.Base', alias: 'data.summary.count', /** * Name of the summary function that appears in the {@link Ext.grid.plugin.Summaries} plugin */ text: 'Count', calculate: function(records, property, root, begin, end) { return end - begin; }});