class_docstr: Test fake binary header defined at top of module
class_docstr_tok: ["Test","fake","binary","header","defined","at","top","of","module"]
code: def test_str(self):
      hdr = self.header_class()
      s1 = str(hdr)
      assert len(s1) > 0
      assert "an_integer" in s1
      assert "a_str" in s1
  
imports: import logging
  from io import BytesIO, StringIO
  import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from ..None import imageglobals
  from ..batteryrunners import Report
  from ..casting import sctypes
  from ..spatialimages import HeaderDataError
  from ..volumeutils import Recoder, native_code, swapped_code
  from ..wrapstruct import LabeledWrapStruct, WrapStruct, WrapStructError
label_desc: Use image node_id 4 for calling the TestMyWrapStruct obj's underlying member method code with example usage: obj.test_str() without return types