如何合并和排序QTreeWidgetItems的两个排序列表?

I have a QTreeWidget with a bunch of QTreeWidgetItems. Each QTreeWidgetItem has a timestamp that is in the form of a QDateTime. The QTreeWidget is sorted by timestamp. I have another list of QTreeWidgetItems that is also sorted by timestamp. I want to add this list of QTreeWidgetItems to my QTreeWidget and end up with combine sorted list of QTreeWIdgetItems in a QTreeWidget. I have a QTreeWidget with a bunch of QTreeWidge