code: def test_sar_ice(self):
      """Test creating a the sar_ice composite."""
      import dask.array as da
      import numpy as np
      import xarray as xr
  
      from satpy.composites.sar import SARIce
  
      rows = 2
      cols = 2
      comp = SARIce(
          "sar_ice", prerequisites=("hh", "hv"), standard_name="sar-ice"
      )
      hh = xr.DataArray(
          da.zeros((rows, cols), chunks=25) + 2000,
          dims=("y", "x"),
          attrs={"name": "hh"},
      )
      hv = xr.DataArray(
          da.zeros((rows, cols), chunks=25) + 1000,
          dims=("y", "x"),
          attrs={"name": "hv"},
      )
  
      res = comp((hh, hv))
      assert isinstance(res, xr.DataArray)
      assert isinstance(res.data, da.Array)
      assert res.attrs["name"] == "sar_ice"
      assert res.attrs["standard_name"] == "sar-ice"
      data = res.compute()
      np.testing.assert_allclose(data.sel(bands="R"), 31.58280822)
      np.testing.assert_allclose(data.sel(bands="G"), 159869.56789876)
      np.testing.assert_allclose(data.sel(bands="B"), 44.68138191)
  
imports: import unittest
label_desc: Use image node_id 1 for calling the TestSARComposites obj's underlying member method code with example usage: obj.test_sar_ice() without return types