class_docstr: GraphicsItem filling the space between two PlotDataItems.
code: def updatePath(self):
      if self.curves is None:
          self.setPath(QtGui.QPainterPath())
          return
      paths = []
      for c in self.curves:
          if isinstance(c, PlotDataItem):
              paths.append(c.curve.getPath())
          elif isinstance(c, PlotCurveItem):
              paths.append(c.getPath())
  
      path = QtGui.QPainterPath()
      transform = QtGui.QTransform()
      ps1 = paths[0].toSubpathPolygons(transform)
      ps2 = paths[1].toReversed().toSubpathPolygons(transform)
      ps2.reverse()
      if len(ps1) == 0 or len(ps2) == 0:
          self.setPath(QtGui.QPainterPath())
          return
  
      for p1, p2 in zip(ps1, ps2):
          path.addPolygon(p1 + p2)
      self.setPath(path)
  
file_path: pyqtgraph/pyqtgraph/graphicsItems/FillBetweenItem.py
imports: from ..None import functions
  from ..Qt import QtGui, QtWidgets
  from .PlotCurveItem import PlotCurveItem
  from .PlotDataItem import PlotDataItem
label_desc: Use image node_id 6 for calling the FillBetweenItem obj's underlying member method code with example usage: obj.updatePath() without return types