Returns the mime data for dragging for this instance.
        
        :param      items | [<QTreeWidgetItem>, ..]

def mimeData(self, items):
        """
        Returns the mime data for dragging for this instance.
        
        :param      items | [<QTreeWidgetItem>, ..]
        """
        func = self.dataCollector()
        if func:
            return func(self, items)
        
        # extract the records from the items
        record_items = []
        for item in self.selectedItems():
            if isinstance(item, XOrbRecordItem):
                record_items.append(item)
        
        # create the mime data
        data = QMimeData()
        self.dataStoreRecords(data, record_items)
        return data