code: def setup_ui(self, ):
          
          w = QtGui.QWidget(self)
          w.setLayout(self.central_widget_vbox)
          self.setCentralWidget(w)
          self.reftrack_treev = WD_TreeView(parent=self)
          self.reftrack_treev.setHeaderHidden(True)
          self.central_widget_vbox.insertWidget(1, self.reftrack_treev)
          self.setup_icons()
          self.model = self.root.get_model()
          self.proxy = self.create_proxy_model(self.model)
          self.proxy.setFilterKeyColumn(-1)  # filter all columns
          self.proxy.setFilterCaseSensitivity(QtCore.Qt.CaseInsensitive)
          self.reftrack_treev.setModel(self.proxy)
          self.reftrack_treev.setItemDelegate(self.reftrackdelegate)
          # hide all columns but the first
          cc = self.proxy.columnCount(QtCore.QModelIndex())
          for i in range(1, cc):
              self.reftrack_treev.setColumnHidden(i, True)
docs: Setup the general ui
  
          :returns: None
          :rtype: None
          :raises: None