code: def _sphere_immersion(point):
      radius = 4.0
      theta = point[0]
      phi = point[1]
      x = gs.sin(theta) * gs.cos(phi)
      y = gs.sin(theta) * gs.sin(phi)
      z = gs.cos(theta)
      return gs.array([radius * x, radius * y, radius * z])
  
imports: import warnings
  import numpy
  import pytest
  import geomstats.backend
  from geomstats.geometry.grassmannian import Grassmannian
  from geomstats.geometry.special_euclidean import SpecialEuclidean
  from geomstats.test.test_case import TestCase, autograd_and_torch_only, autograd_only, np_only
label_desc: Use image node_id 1 for calling a global function with example usage: _sphere_immersion(point) and returns: gs