code: def test_subheader(self):
      assert self.subhdr.get_shape() == (10, 10, 3)
      assert self.subhdr.get_nframes() == 1
      assert self.subhdr.get_nframes() == len(self.subhdr.subheaders)
      assert self.subhdr._check_affines() is True
      assert_array_almost_equal(
          np.diag(self.subhdr.get_frame_affine()),
          np.array([2.20241979, 2.20241979, 3.125, 1.0]),
      )
      assert self.subhdr.get_zooms()[0] == 2.20241978764534
      assert self.subhdr.get_zooms()[2] == 3.125
      assert self.subhdr._get_data_dtype(0) == np.int16
      # assert_equal(self.subhdr._get_frame_offset(), 1024)
      assert self.subhdr._get_frame_offset() == 1536
      dat = self.subhdr.raw_data_from_fileobj()
      assert dat.shape == self.subhdr.get_shape()
      assert self.subhdr.subheaders[0]["scale_factor"].item() == 1.0
      ecat_calib_factor = self.hdr["ecat_calibration_factor"]
      assert ecat_calib_factor == 25007614.0
  
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 2 for calling the TestEcatSubHeader obj's underlying member method code with example usage: obj.test_subheader() without return types