code: def try_to_set_ctx(self, ctx_name):
      try:
          ctx = get_extension_context(ctx_name)
      except Exception as e:
          pytest.skip(
              "Import of nnabla-ext-cuda failed, so skip this test."
          )
  
      nn.set_default_context(ctx)
  
imports: import numpy
  import nnabla
  import pytest
  from nnabla.ext_utils import get_extension_context
  import nnabla.functions
label_desc: Use image node_id 3 for calling the TestNdArrayNarrow obj's underlying member method code with example usage: obj.try_to_set_ctx(ctx_name) without return types