code: def test_convert_to_spherical_coordinates_pre_shape_2d(self):
      points = self.S32.random_point(self.n_samples)
      coords = self.KS.convert_to_spherical_coordinates(points)
      x = coords[:, 0]
      y = coords[:, 1]
      z = coords[:, 2]
      result = x**2 + y**2 + z**2
      expected = 0.25 * gs.ones(self.n_samples)
      self.assertAllClose(result, expected)
  
imports: import matplotlib
  import matplotlib.pyplot
  import geomstats.backend
  import geomstats.visualization
  from geomstats.geometry.hyperbolic import Hyperbolic
  from geomstats.geometry.hypersphere import Hypersphere
  from geomstats.geometry.matrices import Matrices
  from geomstats.geometry.poincare_half_space import PoincareHalfSpace
  from geomstats.geometry.pre_shape import PreShapeSpace
  from geomstats.geometry.spd_matrices import SPDMatrices
  from geomstats.geometry.special_euclidean import SpecialEuclidean
  from geomstats.geometry.special_orthogonal import SpecialOrthogonal, _SpecialOrthogonalMatrices
  from geomstats.test.test_case import TestCase
label_desc: Use image node_id 9 for calling the TestVisualization obj's underlying member method code with example usage: obj.test_convert_to_spherical_coordinates_pre_shape_2d() without return types