code: def test_3D_pathway_to_loads(self):
      self.pB.set_pos(
          self.pA,
          self.q1 * self.N.x
          - self.q2 * self.N.y
          + 2 * self.q3 * self.N.z,
      )
      length = sqrt(self.q1**2 + self.q2**2 + 4 * self.q3**2)
      pO_force = (
          -self.F * self.q1 * self.N.x / length
          + self.F * self.q2 * self.N.y / length
          - 2 * self.F * self.q3 * self.N.z / length
      )
      pI_force = (
          self.F * self.q1 * self.N.x / length
          - self.F * self.q2 * self.N.y / length
          + 2 * self.F * self.q3 * self.N.z / length
      )
      expected = [
          (self.pA, pO_force),
          (self.pB, pI_force),
      ]
      assert self.pathway.to_loads(self.F) == expected
  
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 16 for calling the TestLinearPathway obj's underlying member method code with example usage: obj.test_3D_pathway_to_loads() without return types