code: def test_concatenate_different_dim_number(self):
      inputs = layers.parallel(
          layers.Input((28, 28)),
          layers.Input((28, 28, 1)),
      )
  
      expected_msg = "different number of dimensions"
      with self.assertRaisesRegexp(LayerConnectionError, expected_msg):
          layers.join(inputs, layers.Concatenate(axis=1))
  
file_path: neupy/tests/layers/test_merge.py
imports: import tensorflow
  import numpy
  from neupy import layers
  from neupy.utils import asfloat
  from neupy.exceptions import LayerConnectionError
  from base import BaseTestCase
label_desc: Use image node_id 2 for calling the ConcatenateTestCase obj's underlying member method code with example usage: obj.test_concatenate_different_dim_number() without return types