code: def make_h5_null_string(length):
      """Make a HDF5 type for a NULL terminated string of fixed length."""
      dt = h5py.h5t.TypeID.copy(h5py.h5t.C_S1)
      dt.set_size(7)
      dt.set_strpad(h5py.h5t.STR_NULLTERM)
      return dt
  
file_path: satpy/satpy/tests/reader_tests/test_gerb_l2_hr_h5.py
imports: import h5py
  import numpy
  import pytest
  from satpy import Scene
  from satpy.tests.utils import xfail_h5py_unstable_numpy2
label_desc: Use image node_id 1 for calling a global function with example usage: make_h5_null_string(length) and returns: dt