code: def test_forward_backward(seed, ctx, func_name, upper):
      rng = np.random.RandomState(seed)
      x = rng.randn(2, 4, 4).astype(np.float32)
      for i in range(x.shape[0]):
          x[i] = np.dot(x[i], np.transpose(x[i]))
      inputs = [x]
      function_tester(
          rng,
          F.batch_cholesky,
          batch_cholesky,
          inputs,
          func_args=[upper],
          atol_b=2e-2,
          func_name=func_name,
          ctx=ctx,
          backward=[True],
          ref_grad=batch_cholesky_numerical_grad,
          disable_half_test=True,
      )
  
imports: import pytest
  import numpy
  import nnabla.functions
  from nbla_test_utils import list_context, function_tester
label_desc: Use image node_id 3 for calling a global function with example usage: test_forward_backward(seed, ctx, func_name, upper) without return types