code: def belongs_test_data(self):
      data = [
          dict(
              point=gs.array(
                  [
                      [
                          [1.0, 0.0, 1.0],
                          [0.0, 1.0, 0.0],
                          [0.0, 0.0, 1.0],
                      ],
                      [
                          [0.0, 0.0, 0.0],
                          [2.0, 1.0, 0.0],
                          [0.0, 0.0, 1.0],
                      ],
                      [
                          [1.0, 0.0, 0.0],
                          [2.0, 1.0, 0.0],
                          [0.0, 0.0, 1.0],
                      ],
                      [
                          [-1.0, 0.0, 0.0],
                          [2.0, 1.0, 0.0],
                          [0.0, 0.0, 1.0],
                      ],
                  ]
              ),
              expected=[False, True, True, True],
          ),
          dict(
              point=gs.array([[1.0, 0.0], [-1.0, 3.0]]),
              expected=gs.array(False),
          ),
      ]
      return self.generate_tests(data)
  
file_path: geomstats/tests/tests_geomstats/test_geometry/data/lower_triangular_matrices.py
imports: import geomstats.backend
  from geomstats.test.data import TestData
  from .base import MatrixVectorSpaceTestData
label_desc: Use image node_id 1 for calling the LowerTriangularMatrices3TestData obj's underlying member method code with example usage: obj.belongs_test_data() and returns: self