code: def layer(self, axis):
      from lasagne.layers.merge import ConcatLayer
  
      return ConcatLayer([Mock(), Mock()], axis=axis)
  
imports: from mock import Mock
  import numpy
  import pytest
  import theano
label_desc: Use image node_id 1 for calling the TestConcatLayer obj's underlying member method code with example usage: obj.layer(axis) and returns: ConcatLayer