code: def test_sofm_n_outputs_as_optional_parameter(self):
      sofm = algorithms.SOFM(
          n_inputs=2,
          features_grid=(10, 2, 3),
      )
      self.assertEqual(60, sofm.n_outputs)
  
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 13 for calling the SOFMTestCase obj's underlying member method code with example usage: obj.test_sofm_n_outputs_as_optional_parameter() without return types