code: def _get_bcpIn(self):
          
          segment = self._segment
          offCurves = segment.offCurve
          if offCurves:
              bcp = offCurves[-1]
              x, y = relativeBCPIn(self.anchor, (bcp.x, bcp.y))
          else:
              x = y = 0
          return (x, y)
docs: Subclasses may override this method.