Method _get_angle

graph.py:1122–1128

(
      self, d1: Direction, d2: Direction
  )

    return not nm.check_para([p.num for p in points])

  def _get_angle(
      self, d1: Direction, d2: Direction
  ) -> tuple[Angle, Optional[Angle]]:
    for a in self.type2nodes[Angle]:
      if a.directions == (d1, d2):
        return a, a.opposite
    return None, None

  def get_first_angle(
      self, l1: Line, l2: Line