code: def test_nd_array_narrow_array_class_cpu(self, ctx_name):
      self.try_to_set_ctx(ctx_name)
  
      ctx = nn.get_current_context()
  
      ctx.array_class = "CpuArray"
      a = nn.NdArray(2, 5)
      a.cast(np.float32, ctx=ctx)
      # No error
      b = a.narrow(0, 0, 1)
  
      ctx.array_class = "CpuCachedArray"
      a = nn.NdArray(2, 5)
      a.cast(np.float32, ctx=ctx)
      # No error
      b = a.narrow(0, 0, 1)
  
imports: import numpy
  import nnabla
  import pytest
  from nnabla.ext_utils import get_extension_context
  import nnabla.functions
label_desc: Use image node_id 13 for calling the TestNdArrayNarrow obj's underlying member method code with example usage: obj.test_nd_array_narrow_array_class_cpu(ctx_name) without return types