code: def test_checks(self):
      # Test header checks
      hdr_t = self.header_class()
      # _dxer just returns the diagnostics as a string
      assert self._dxer(hdr_t) == ""
      hdr = hdr_t.copy()
      hdr["sizeof_hdr"] = 1
      with suppress_warnings():
          assert self._dxer(hdr) == "sizeof_hdr should be " + str(
              self.sizeof_hdr
          )
      hdr = hdr_t.copy()
      hdr["datatype"] = 0
      assert (
          self._dxer(hdr)
          == "data code 0 not supported\nbitpix does not match datatype"
      )
      hdr = hdr_t.copy()
      hdr["bitpix"] = 0
      assert self._dxer(hdr) == "bitpix does not match datatype"
  
imports: import itertools
  import logging
  import os
  import pickle
  import re
  from io import BytesIO, StringIO
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from ..None import imageglobals
  from ..analyze import AnalyzeHeader, AnalyzeImage
  from ..arraywriters import WriterError
  from ..casting import sctypes_aliases
  from ..nifti1 import Nifti1Header
  from ..optpkg import optional_package
  from ..spatialimages import HeaderDataError, HeaderTypeError, supported_np_types
  from ..testing import assert_dt_equal, bytesio_filemap, bytesio_round_trip, data_path, suppress_warnings
  from ..tmpdirs import InTemporaryDirectory
  from .None import test_spatialimages
  from .None import test_wrapstruct
label_desc: Use image node_id 7 for calling the TestAnalyzeHeader obj's underlying member method code with example usage: obj.test_checks() without return types