code: def get_h5_dataset(fn):
      """
      Hdf loading ilastik style is copied from:
      https://github.com/ilastik/ilastik/blob/master/bin/concatenate-hdf5-volumes.py
      Return the only dataset in the hdf5 file.
      If there's more than one, it's an error.
      """
      with h5py.File(fn, "r") as f:
          dataset_names = []
          f.visit(dataset_names.append)
          assert (
              len(dataset_names) == 1
          ), "Input HDF5 file should have exactly 1 dataset, but {} has {} datasets\n".format(
              f.filename, len(dataset_names)
          )
          data = f[dataset_names[0]][:]
      return data
  
imports: import io
  import os.path
  import h5py
  import numpy
  import numpy.random
  import numpy.testing
  import pytest
  import skimage.data
  import skimage.util
  import cellprofiler_core.image
  import cellprofiler.modules.saveimages
  import cellprofiler_core.pipeline
  import cellprofiler_core.setting
  import cellprofiler_core.preferences
label_desc: Use image node_id 18 for calling a global function with example usage: get_h5_dataset(fn) and returns: data