code: def test_mul_identity(self, n_points, atol):
      mat_a = self.data_generator.random_mat(n_points)
      identity = gs.eye(mat_a.shape[-1])
  
      self.test_mul(mat_a, identity, mat_a, atol)
  
imports: import pytest
  import geomstats.backend
  from geomstats.geometry.matrices import Matrices
  from geomstats.test.test_case import TestCase
  from geomstats.test.vectorization import generate_vectorization_data
  from geomstats.test_cases.geometry.base import MatrixVectorSpaceTestCase
  from geomstats.test_cases.geometry.euclidean import EuclideanMetricTestCase
label_desc: Use image node_id 9 for calling the MatrixOperationsTestCase obj's underlying member method code with example usage: obj.test_mul_identity(n_points, atol) without return types