code: def test_show_examples_raises_on_wrong_column_labels(self):
      output_prefix = test_utils.test_tmpfile("column_labels")
      FLAGS.examples = testdata.GOLDEN_TRAINING_EXAMPLES
      FLAGS.output = output_prefix
      FLAGS.column_labels = (
          "read base,base quality,mapping quality,strand"
      )
      with self.assertRaisesRegex(ValueError, "--column_labels"):
          show_examples.run()
  
      # With 6 channel names, it should run without error:
      FLAGS.column_labels = "1,2,3,4,5,6"
      show_examples.run()
  
imports: import glob
  import os
  from absl import flags
  from absl.testing import absltest
  from absl.testing import flagsaver
  from absl.testing import parameterized
  from deepvariant import show_examples
  from deepvariant import testdata
  from third_party.nucleus.testing import test_utils
label_desc: Use image node_id 4 for calling the ShowExamplesEnd2EndTest obj's underlying member method code with example usage: obj.test_show_examples_raises_on_wrong_column_labels() without return types