How to use the plottr.QtWidgets.QTreeWidgetItem function in plottr

def add(parent, name):
            item = self.find(parent, name)
            if item is None:
                item = QtWidgets.QTreeWidgetItem(parent, [name])
                if os.path.splitext(name)[-1] in self.fileExtensions:
                    fnt = QtGui.QFont()
                    item.setFont(0, fnt)
                else:
                    pass
                if isinstance(parent, DataFileList):
                    parent.addTopLevelItem(item)
                else:
                    parent.addChild(item)
            return item

for grpName, grpData in data.items():
            self.data[grpName] = data[grpName]
            grpItem = QtWidgets.QTreeWidgetItem(self, [grpName])
            self.groupItems.append(grpItem)
            self.addTopLevelItem(grpItem)
            dataParent = QtWidgets.QTreeWidgetItem(grpItem, ['[DATA]'])
            metaParent = QtWidgets.QTreeWidgetItem(grpItem, ['[META]'])

            for dn, dv in grpData.data_items():
                vals = [grpData.label(dn), str(grpData.meta_val('shape', dn))]
                if dn in grpData.dependents():
                    vals.append(f'Data (depends on {str(tuple(grpData.axes(dn)))[1:]}')
                else:
                    vals.append('Data (independent)')
                ditem = QtWidgets.QTreeWidgetItem(dataParent, vals)

                for mn, mv in grpData.meta_items(dn):
                    vals = [mn, str(mv)]
                    _ = QtWidgets.QTreeWidgetItem(ditem, vals)

            for mn, mv in grpData.meta_items():
                vals = [mn, str(mv)]
                _ = QtWidgets.QTreeWidgetItem(metaParent, vals)

            grpItem.setExpanded(True)
            dataParent.setExpanded(True)

        for i in range(self.columnCount()-1):
            self.resizeColumnToContents(i)

def setData(self, data: Dict[str, DataDict]):
        """Set the data to display."""
        self.clear()
        self.data = {}
        self.groupItems = []

        for grpName, grpData in data.items():
            self.data[grpName] = data[grpName]
            grpItem = QtWidgets.QTreeWidgetItem(self, [grpName])
            self.groupItems.append(grpItem)
            self.addTopLevelItem(grpItem)
            dataParent = QtWidgets.QTreeWidgetItem(grpItem, ['[DATA]'])
            metaParent = QtWidgets.QTreeWidgetItem(grpItem, ['[META]'])

            for dn, dv in grpData.data_items():
                vals = [grpData.label(dn), str(grpData.meta_val('shape', dn))]
                if dn in grpData.dependents():
                    vals.append(f'Data (depends on {str(tuple(grpData.axes(dn)))[1:]}')
                else:
                    vals.append('Data (independent)')
                ditem = QtWidgets.QTreeWidgetItem(dataParent, vals)

                for mn, mv in grpData.meta_items(dn):
                    vals = [mn, str(mv)]
                    _ = QtWidgets.QTreeWidgetItem(ditem, vals)

            for mn, mv in grpData.meta_items():
                vals = [mn, str(mv)]

self.groupItems.append(grpItem)
            self.addTopLevelItem(grpItem)
            dataParent = QtWidgets.QTreeWidgetItem(grpItem, ['[DATA]'])
            metaParent = QtWidgets.QTreeWidgetItem(grpItem, ['[META]'])

            for dn, dv in grpData.data_items():
                vals = [grpData.label(dn), str(grpData.meta_val('shape', dn))]
                if dn in grpData.dependents():
                    vals.append(f'Data (depends on {str(tuple(grpData.axes(dn)))[1:]}')
                else:
                    vals.append('Data (independent)')
                ditem = QtWidgets.QTreeWidgetItem(dataParent, vals)

                for mn, mv in grpData.meta_items(dn):
                    vals = [mn, str(mv)]
                    _ = QtWidgets.QTreeWidgetItem(ditem, vals)

            for mn, mv in grpData.meta_items():
                vals = [mn, str(mv)]
                _ = QtWidgets.QTreeWidgetItem(metaParent, vals)

            grpItem.setExpanded(True)
            dataParent.setExpanded(True)

        for i in range(self.columnCount()-1):
            self.resizeColumnToContents(i)

for dn, dv in grpData.data_items():
                vals = [grpData.label(dn), str(grpData.meta_val('shape', dn))]
                if dn in grpData.dependents():
                    vals.append(f'Data (depends on {str(tuple(grpData.axes(dn)))[1:]}')
                else:
                    vals.append('Data (independent)')
                ditem = QtWidgets.QTreeWidgetItem(dataParent, vals)

                for mn, mv in grpData.meta_items(dn):
                    vals = [mn, str(mv)]
                    _ = QtWidgets.QTreeWidgetItem(ditem, vals)

            for mn, mv in grpData.meta_items():
                vals = [mn, str(mv)]
                _ = QtWidgets.QTreeWidgetItem(metaParent, vals)

            grpItem.setExpanded(True)
            dataParent.setExpanded(True)

        for i in range(self.columnCount()-1):
            self.resizeColumnToContents(i)

def remove(i):
            parent = i.parent()
            if isinstance(parent, DataFileList):
                idx = parent.indexOfTopLevelItem(i)
                parent.takeTopLevelItem(idx)
            elif isinstance(parent, QtWidgets.QTreeWidgetItem):
                parent.removeChild(i)
                if parent.childCount() == 0:
                    remove(parent)