code: def test_center_of_mass():
      a = ReferenceFrame("a")
      m = symbols("m", real=True)
      p1 = Particle("p1", Point("p1_pt"), S.One)
      p2 = Particle("p2", Point("p2_pt"), S(2))
      p3 = Particle("p3", Point("p3_pt"), S(3))
      p4 = Particle("p4", Point("p4_pt"), m)
      b_f = ReferenceFrame("b_f")
      b_cm = Point("b_cm")
      mb = symbols("mb")
      b = RigidBody("b", b_cm, b_f, mb, (outer(b_f.x, b_f.x), b_cm))
      p2.point.set_pos(p1.point, a.x)
      p3.point.set_pos(p1.point, a.x + a.y)
      p4.point.set_pos(p1.point, a.y)
      b.masscenter.set_pos(p1.point, a.y + a.z)
      point_o = Point("o")
      point_o.set_pos(
          p1.point, center_of_mass(p1.point, p1, p2, p3, p4, b)
      )
      expr = (
          5 / (m + mb + 6) * a.x
          + (m + mb + 3) / (m + mb + 6) * a.y
          + mb / (m + mb + 6) * a.z
      )
      assert point_o.pos_from(p1.point) - expr == 0
  
file_path: sympy/sympy/physics/mechanics/tests/test_functions.py
imports: from sympy import sin, cos, tan, pi, symbols, Matrix, S, Function
  from sympy.physics.mechanics import Particle, Point, ReferenceFrame, RigidBody
  from sympy.physics.mechanics import angular_momentum, dynamicsymbols, kinetic_energy, linear_momentum, outer, potential_energy, msubs, find_dynamicsymbols, Lagrangian
  from sympy.physics.mechanics.functions import center_of_mass, _validate_coordinates, _parse_linear_solver
  from sympy.testing.pytest import raises, warns_deprecated_sympy
label_desc: Use image node_id 8 for calling a global function with example usage: test_center_of_mass() without return types