class_docstr: Test case for CF writer.
docstr: Test saving an array to netcdf/cf where dataset name starting with a digit.
docstr_tok: ["Test","saving","an","array","to","netcdf\/cf","where","dataset","name","starting","with","a","digit","."]
code: def test_save_dataset_a_digit(self):
      """Test saving an array to netcdf/cf where dataset name starting with a digit."""
      scn = Scene()
      scn["1"] = xr.DataArray([1, 2, 3])
      with TempFile() as filename:
          scn.save_datasets(filename=filename, writer="cf")
          with xr.open_dataset(filename) as f:
              np.testing.assert_array_equal(
                  f["CHANNEL_1"][:], [1, 2, 3]
              )
  
imports: import os
  import tempfile
  import warnings
  from datetime import datetime
  import numpy
  import pytest
  import xarray
  from packaging.version import Version
  from satpy import Scene
  from satpy.tests.utils import make_dsq
  from satpy.writers.cf_writer import _get_backend_versions
label_desc: Use image node_id 4 for calling the TestCFWriter obj's underlying member method code with example usage: obj.test_save_dataset_a_digit() without return types