code: def test_bracket_vec(self, n_reps, atol):
      mat_a = self.data_generator.random_square_mat()
      mat_b = self.data_generator.random_square_mat(
          shape=mat_a.shape[-2:]
      )
  
      expected = Matrices.bracket(mat_a, mat_b)
  
      vec_data = generate_vectorization_data(
          data=[
              dict(
                  mat_a=mat_a, mat_b=mat_b, expected=expected, atol=atol
              )
          ],
          arg_names=["mat_a", "mat_b"],
          expected_name="expected",
          n_reps=n_reps,
      )
      self._test_vectorization(vec_data)
  
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 11 for calling the MatrixOperationsTestCase obj's underlying member method code with example usage: obj.test_bracket_vec(n_reps, atol) without return types