code: def _expected_sphere_metric_matrix(point):
      theta = point[..., 0]
      mat = gs.array([[1.0, 0.0], [0.0, gs.sin(theta) ** 2]])
      return mat
  
imports: import geomstats.backend
  from geomstats.test.data import TestData
  from .riemannian_metric import RiemannianMetricComparisonTestData, RiemannianMetricTestData
label_desc: Use image node_id 5 for calling a global function with example usage: _expected_sphere_metric_matrix(point) and returns: mat