class_docstr: Test locating the satellite.
docstr: Get an orbit polynomial for testing.
docstr_tok: ["Get","an","orbit","polynomial","for","testing","."]
code: def orbit_polynomial(self):
      """Get an orbit polynomial for testing."""
      return OrbitPolynomial(
          start_time=datetime(2006, 1, 1, 12),
          end_time=datetime(2006, 1, 1, 18),
          coefs=(
              np.array(
                  [
                      8.41607082e04,
                      2.94319260e00,
                      9.86748617e-01,
                      -2.70135453e-01,
                      -3.84364650e-02,
                      8.48718433e-03,
                      7.70548174e-04,
                      -1.44262718e-04,
                  ]
              ),
              np.array(
                  [
                      -5.21170255e03,
                      5.12998948e00,
                      -1.33370453e00,
                      -3.09634144e-01,
                      6.18232793e-02,
                      7.50505681e-03,
                      -1.35131011e-03,
                      -1.12054405e-04,
                  ]
              ),
              np.array(
                  [
                      -6.51293855e02,
                      1.45830459e02,
                      5.61379400e01,
                      -3.90970565e00,
                      -7.38137565e-01,
                      3.06131644e-02,
                      3.82892428e-03,
                      -1.12739309e-04,
                  ]
              ),
          ),
      )
  
imports: import unittest
  from datetime import datetime, timedelta
  import dask.array
  import numpy
  import pytest
  import xarray
  from satpy.readers.seviri_base import MEIRINK_COEFS, MEIRINK_EPOCH, NoValidOrbitParams, OrbitPolynomial, OrbitPolynomialFinder, SEVIRICalibrationHandler, chebyshev, dec10216, get_cds_time, get_padding_area, get_satpos, pad_data_horizontally, pad_data_vertically, round_nom_time
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 1 for calling the TestSatellitePosition obj's underlying member method code with example usage: obj.orbit_polynomial() and returns: OrbitPolynomial