Subclasses may override this method.

def _setStartSegment(self, segmentIndex, **kwargs):
        """
        Subclasses may override this method.
        """
        segments = self.segments
        oldStart = segments[-1]
        oldLast = segments[0]
        # If the contour ends with a curve on top of a move,
        # delete the move.
        if oldLast.type == "curve" or oldLast.type == "qcurve":
            startOn = oldStart.onCurve
            lastOn = oldLast.onCurve
            if startOn.x == lastOn.x and startOn.y == lastOn.y:
                self.removeSegment(0)
                # Shift new the start index.
                segmentIndex = segmentIndex - 1
                segments = self.segments
        # If the first point is a move, convert it to a line.
        if segments[0].type == "move":
            segments[0].type = "line"
        # Reorder the points internally.
        segments = segments[segmentIndex - 1:] + segments[:segmentIndex - 1]
        points = []
        for segment in segments:
            for point in segment:
                points.append(((point.x, point.y), point.type,
                               point.smooth, point.name, point.identifier))
        # Clear the points.
        for point in self.points:
            self.removePoint(point)
        # Add the points.
        for point in points:
            position, type, smooth, name, identifier = point
            self.appendPoint(
                position,
                type=type,
                smooth=smooth,
                name=name,
                identifier=identifier
            )