code: def init(self, clear: bool = True) -> None:
      if self.import_vtk is False:
          return
      # remove
      item = self.vlayer.itemAt(0)
      self.vlayer.removeItem(item)
      if item is not None and item.widget():
          item.widget().deleteLater()
      # add
      self.renderer = vtk.vtkRenderer()
      self.interactor = QVTKRenderWindowInteractor(self)
      self.interactor.GetRenderWindow().AddRenderer(self.renderer)
      self.vlayer.addWidget(self.interactor)
      if clear:
          # set background
          self.renderer.SetBackground(
              vtk.vtkNamedColors().GetColor3d("black")
          )
          self.interactor.Start()
  
file_path: PaddleSeg/EISeg/eiseg/widget/vtk.py
imports: import typing
  import numpy
  from qtpy.QtWidgets import QWidget, QVBoxLayout
label_desc: Use image node_id 3 for calling the VTKWidget obj's underlying member method code with example usage: obj.init(clear) without return types