code: def test_bars_unequal_keydims(self):
      try:
          self.assertEqual(self.bars1, self.bars3)
      except AssertionError as e:
          if (
              not str(e)
              == "Dimension names mismatched: Car occupants != Cyclists"
          ):
              raise Exception(
                  "Bars key dimension mismatch error not raised."
              )
  
imports: import numpy
  from holoviews import Bars, Curve, Dimension, Histogram, Points, Scatter, VectorField
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 6 for calling the BarsComparisonTest obj's underlying member method code with example usage: obj.test_bars_unequal_keydims() without return types