code: def test_concatenate_forward_backward(
      seed, axis, different_size, num_inputs, ctx, func_name
  ):
      from nbla_test_utils import cap_ignore_region, function_tester
  
      rng = np.random.RandomState(seed)
      shape0 = [2, 3, 4]
      inputs = []
      for i in range(num_inputs):
          inputs.append(rng.randn(*shape0).astype(np.float32))
          shape0[axis] += int(different_size)
      function_tester(
          rng,
          F.concatenate,
          ref_concatenate,
          inputs,
          func_kwargs=dict(axis=axis),
          ctx=ctx,
          func_name=func_name,
          atol_b=1e-2,
      )
  
file_path: nnabla/python/test/function/test_concatenate.py
imports: import pytest
  import numpy
  import nnabla
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 2 for calling a global function with example usage: test_concatenate_forward_backward(seed, axis, different_size, num_inputs, ctx, func_name) without return types