code: def test_abs_forward_backward(seed, ctx, func_name):
      from nbla_test_utils import cap_ignore_region, function_tester
  
      rng = np.random.RandomState(seed)
      inputs = []
      for _ in range(2):
          inputs.append(
              rng.randn(
                  2,
                  3,
              ).astype(np.float32)
              * 2
          )
  
      function_tester(
          rng,
          F.absolute_error,
          lambda x, y: np.abs(x - y),
          inputs,
          ctx=ctx,
          func_name=func_name,
          atol_b=1e-2,
      )
  
imports: import pytest
  import numpy
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 1 for calling a global function with example usage: test_abs_forward_backward(seed, ctx, func_name) without return types