docstr: Test that nested structured types are treated as records too 
docstr_tok: ["Test","that","nested","structured","types","are","treated","as","records","too"]
code: def test_nested_fields_are_records(self, nfields):
      """Test that nested structured types are treated as records too"""
      dt = np.dtype(
          [("a", np.uint8), ("b", np.uint8), ("c", np.uint8)][:nfields]
      )
      dt_outer = np.dtype([("inner", dt)])
  
      data = np.zeros(3, dt_outer).view(np.recarray)
      assert isinstance(data, np.recarray)
      assert isinstance(data["inner"], np.recarray)
  
      data0 = data[0]
      assert isinstance(data0, np.record)
      assert isinstance(data0["inner"], np.record)
  
imports: import collections.abc
  import textwrap
  from io import BytesIO
  from os import path
  from pathlib import Path
  import pytest
  import numpy
  from numpy.testing import assert_, assert_equal, assert_array_equal, assert_array_almost_equal, assert_raises, temppath
  from numpy.compat import pickle
label_desc: Use image node_id 16 for calling the TestRecord obj's underlying member method code with example usage: obj.test_nested_fields_are_records(nfields) without return types