How to use the svgpathtools.path.CubicBezier function in svgpathtools

def split(self, t):
        """returns two segments, whose union is this segment and which join at
        self.point(t)."""
        bpoints1, bpoints2 = split_bezier(self.bpoints(), t)
        return CubicBezier(*bpoints1), CubicBezier(*bpoints2)

def bpoints2bezier(bpoints):
    """Converts a list of length 2, 3, or 4 to a CubicBezier, QuadraticBezier,
    or Line object, respectively.
    See also: poly2bez."""
    order = len(bpoints) - 1
    if order == 3:
        return CubicBezier(*bpoints)
    elif order == 2:
        return QuadraticBezier(*bpoints)
    elif order == 1:
        return Line(*bpoints)
    else:
        assert len(bpoints) in {2, 3, 4}

def bezier_segment(*bpoints):
    if len(bpoints) == 2:
        return Line(*bpoints)
    elif len(bpoints) == 4:
        return CubicBezier(*bpoints)
    elif len(bpoints) == 3:
        return QuadraticBezier(*bpoints)
    else:
        assert len(bpoints) in (2, 3, 4)

def cropped(self, t0, t1):
        """returns a cropped copy of this segment which starts at
        self.point(t0) and ends at self.point(t1)."""
        return CubicBezier(*crop_bezier(self, t0, t1))

# coincident with the current point.
                control1 = current_pos
            else:
                # The first control point is assumed to be the reflection of
                # the second control point on the previous command relative
                # to the current point.
                control1 = current_pos + current_pos - segments[-1].control2

            control2 = float(elements.pop()) + float(elements.pop()) * 1j
            end = float(elements.pop()) + float(elements.pop()) * 1j

            if not absolute:
                control2 += current_pos
                end += current_pos

            segments.append(CubicBezier(current_pos, control1, control2, end))
            current_pos = end

        elif command == 'Q':
            control = float(elements.pop()) + float(elements.pop()) * 1j
            end = float(elements.pop()) + float(elements.pop()) * 1j

            if not absolute:
                control += current_pos
                end += current_pos

            segments.append(QuadraticBezier(current_pos, control, end))
            current_pos = end

        elif command == 'T':
            # Smooth curve. Control point is the "reflection" of
            # the second control point in the previous path.

def is_bezier_segment(seg):
    return (isinstance(seg, Line) or
            isinstance(seg, QuadraticBezier) or
            isinstance(seg, CubicBezier))

if not absolute:
                pos += current_pos.imag * 1j
            segments.append(Line(current_pos, pos))
            current_pos = pos

        elif command == 'C':
            control1 = float(elements.pop()) + float(elements.pop()) * 1j
            control2 = float(elements.pop()) + float(elements.pop()) * 1j
            end = float(elements.pop()) + float(elements.pop()) * 1j

            if not absolute:
                control1 += current_pos
                control2 += current_pos
                end += current_pos

            segments.append(CubicBezier(current_pos, control1, control2, end))
            current_pos = end

        elif command == 'S':
            # Smooth curve. First control point is the "reflection" of
            # the second control point in the previous path.

            if last_command not in 'CS':
                # If there is no previous command or if the previous command
                # was not an C, c, S or s, assume the first control point is
                # coincident with the current point.
                control1 = current_pos
            else:
                # The first control point is assumed to be the reflection of
                # the second control point on the previous command relative
                # to the current point.
                control1 = current_pos + current_pos - segments[-1].control2

def reversed(self):
        """returns a copy of the CubicBezier object with its orientation
        reversed."""
        new_cub = CubicBezier(self.end, self.control2, self.control1,
                              self.start)
        if self._length_info['length']:
            new_cub._length_info = self._length_info
            new_cub._length_info['bpoints'] = (
                self.end, self.control2, self.control1, self.start)
        return new_cub