code: def _pad_data(self):
      func_name = "pad"
  
      n, m = 2, 3
      args = [
          (gs.ones((n, n)), [[0, 1], [0, 1]]),
          (gs.ones((n, n)), [[0, 1], [0, 0]]),
          (gs.ones((m, n, n)), [[0, 0], [0, 1], [0, 1]]),
      ]
      expected = [(n + 1, n + 1), (n + 1, n), (m, n + 1, n + 1)]
  
      return [
          {"func_name": func_name, "args": args_, "expected": expected_}
          for args_, expected_ in zip(args, expected)
      ]
  
file_path: geomstats/tests/tests_geomstats/test_backend/data/backend.py
imports: import geomstats.backend
  from geomstats.geometry.matrices import Matrices
  from geomstats.geometry.spd_matrices import SPDMatrices
  from geomstats.geometry.special_orthogonal import SpecialOrthogonal
  from geomstats.geometry.symmetric_matrices import SymmetricMatrices
  from geomstats.test.data import TestData
label_desc: Use image node_id 6 for calling the BackendTestData obj's underlying member method code with example usage: obj._pad_data() and returns: unknown