code: def test_2D_pathway_length(self):
      self.pA.set_pos(self.pO, -(self.N.x + self.N.y))
      self.pB.set_pos(
          self.pO, cos(self.q) * self.N.x - (sin(self.q) + 1) * self.N.y
      )
      self.pI.set_pos(
          self.pO, sin(self.q) * self.N.x + (cos(self.q) - 1) * self.N.y
      )
      pathway = ObstacleSetPathway(self.pO, self.pA, self.pB, self.pI)
      expected = 2 * sqrt(2) + sqrt(2 + 2 * cos(self.q))
      assert (pathway.length - expected).simplify() == 0
  
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 11 for calling the TestObstacleSetPathway obj's underlying member method code with example usage: obj.test_2D_pathway_length() without return types