code: def test_incorrect_data(self):
      self.assertRaises(ValueError, rock, [], 0.1, 2)
  
imports: import unittest
  import matplotlib
  from pyclustering.cluster.rock import rock
  from pyclustering.cluster.tests.rock_templates import RockTestTemplates
  from pyclustering.samples.definitions import SIMPLE_SAMPLES
label_desc: Use image node_id 11 for calling the RockUnitTest obj's underlying member method code with example usage: obj.test_incorrect_data() without return types