code: def _insertBPoint(self, index, type, anchor, bcpIn, bcpOut, **kwargs):
          
          # insert a simple line segment at the given anchor
          # look it up as a bPoint and change the bcpIn and bcpOut there
          # this avoids code duplication
          self._insertSegment(index=index, type="line",
                              points=[anchor], smooth=False)
          bPoints = self.bPoints
          index += 1
          if index >= len(bPoints):
              # its an append instead of an insert
              # so take the last bPoint
              index = -1
          bPoint = bPoints[index]
          bPoint.bcpIn = bcpIn
          bPoint.bcpOut = bcpOut
          bPoint.type = type
docs: Subclasses may override this method.