code: def test_valid_constructor(num_attachments, attachments):
      instance = ObstacleSetPathway(*attachments)
      assert isinstance(instance, ObstacleSetPathway)
      assert hasattr(instance, "attachments")
      assert len(instance.attachments) == num_attachments
      for attachment in instance.attachments:
          assert isinstance(attachment, Point)
  
imports: import pytest
  from sympy import Rational, Symbol, cos, pi, sin, sqrt
  from sympy.physics.mechanics import Force, LinearPathway, ObstacleSetPathway, PathwayBase, Point, ReferenceFrame, WrappingCylinder, WrappingGeometryBase, WrappingPathway, WrappingSphere, dynamicsymbols
  from sympy.simplify.simplify import simplify
label_desc: Use image node_id 2 for calling the TestObstacleSetPathway obj's underlying member method code with example usage: obj.test_valid_constructor(num_attachments, attachments) without return types