code: def _set_something_into_hdr(self, hdr):
      # Called from test_bytes test method.  Specific to the header data type
      hdr["scan_start_time"] = 42
  
imports: import os
  import warnings
  from pathlib import Path
  from unittest import TestCase
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from ..ecat import EcatHeader, EcatImage, EcatSubHeader, get_frame_order, get_series_framenumbers, read_mlist
  from ..openers import Opener
  from ..testing import data_path, suppress_warnings
  from ..tmpdirs import InTemporaryDirectory
  from .None import test_wrapstruct
  from .test_fileslice import slicer_samples
label_desc: Use image node_id 3 for calling the TestEcatHeader obj's underlying member method code with example usage: obj._set_something_into_hdr(hdr) without return types