class_docstr: The ninjo tiff writer tests.
class_docstr_tok: ["The","ninjo","tiff","writer","tests","."]
docstr: Test that unit conversion to themselves do nothing.
docstr_tok: ["Test","that","unit","conversion","to","themselves","do","nothing","."]
code: def test_convert_units_self(self):
      """Test that unit conversion to themselves do nothing."""
      from satpy.tests.utils import make_fake_scene
      from satpy.writers.ninjotiff import convert_units
  
      # ensure that converting from % to itself does not change the data
      sc = make_fake_scene(
          {"VIS006": np.arange(25, dtype="f4").reshape(5, 5)},
          common_attrs={"units": "%"},
      )
      ds_in = sc["VIS006"]
      ds_out = convert_units(ds_in, "%", "%")
      np.testing.assert_array_equal(ds_in, ds_out)
      assert ds_in.attrs == ds_out.attrs
  
file_path: satpy/satpy/tests/writer_tests/test_ninjotiff.py
imports: import sys
  import unittest
  from unittest import mock
  import numpy
  import pytest
  import xarray
label_desc: Use image node_id 5 for calling the TestNinjoTIFFWriter obj's underlying member method code with example usage: obj.test_convert_units_self() without return types