code: def test_sofm_gaussian_neighbour_3d(self):
      expected_result = np.array(
          [
              [
                  [0.85286420, 0.90190947, 0.85286420],
                  [0.90190947, 0.95095473, 0.90190947],
                  [0.85286420, 0.90190947, 0.85286420],
              ],
              [
                  [0.90190947, 0.95095473, 0.90190947],
                  [0.95095473, 1.00000000, 0.95095473],
                  [0.90190947, 0.95095473, 0.90190947],
              ],
              [
                  [0.85286420, 0.90190947, 0.85286420],
                  [0.90190947, 0.95095473, 0.90190947],
                  [0.85286420, 0.90190947, 0.85286420],
              ],
          ]
      )
      actual_result = sofm.find_step_scaler_on_rect_grid(
          grid=np.zeros((3, 3, 3)), center=(1, 1, 1), std=1
      )
  
      np.testing.assert_array_almost_equal(
          expected_result, actual_result
      )
  
imports: import math
  import numpy
  from neupy import algorithms
  from neupy.exceptions import WeightInitializationError
  from neupy.algorithms.competitive import sofm
  from neupy.algorithms.competitive.neighbours import gaussian_df
  from base import BaseTestCase
label_desc: Use image node_id 7 for calling the SOFMNeigboursTestCase obj's underlying member method code with example usage: obj.test_sofm_gaussian_neighbour_3d() without return types