class_docstr: Test the IciL1bNCFileHandler reader.
class_docstr_tok: ["Test","the","IciL1bNCFileHandler","reader","."]
docstr: Test orthorectify.
docstr_tok: ["Test","orthorectify","."]
code: def test_orthorectify(self, reader):
      """Test orthorectify."""
      variable = xr.DataArray(
          np.ones((N_SCAN, N_SAMPLES, N_HORNS)),
          dims=("y", "x", "n_horns"),
          coords={"n_horns": np.arange(N_HORNS)},
      )
      variable = variable.sel({"n_horns": 0})
      orthorect_data_name = "data/navigation_data/delta_longitude"
      orthorectified = reader._orthorectify(
          variable,
          orthorect_data_name,
      )
      np.testing.assert_allclose(orthorectified, 1.009, rtol=1e-5)
  
imports: from datetime import datetime
  from unittest.mock import patch
  import numpy
  import pytest
  import xarray
  from netCDF4 import Dataset
  from satpy.readers.ici_l1b_nc import IciL1bNCFileHandler, InterpolationType
label_desc: Use image node_id 28 for calling the TestIciL1bNCFileHandler obj's underlying member method code with example usage: obj.test_orthorectify(reader) without return types