Returns the group data object for the group to which the passed record belongs **if the Store is grouped**.

@param {Ext.data.Model} record The record for which to return group information.
@return {Object} A single group data block as returned from {@link Ext.data.Store#getGroups Store.getGroups}. Returns
`undefined` if the Store is not grouped.
function(record) {
        var grouper = this.view.store.groupers.first();
        if (grouper) {
            return this.groupCache[grouper.getGroupString(record)];
        }
    }