code: def test_incorrect_data(self):
      self.assertRaises(ValueError, somsc, [], 1, 1)
  
imports: import unittest
  import matplotlib
  from pyclustering.cluster.somsc import somsc
  from pyclustering.cluster.tests.somsc_templates import SyncnetTestTemplates
  from pyclustering.samples.definitions import SIMPLE_SAMPLES
label_desc: Use image node_id 18 for calling the SomscUnitTest obj's underlying member method code with example usage: obj.test_incorrect_data() without return types