class_docstr: Test VISSR file handler.
class_docstr_tok: ["Test","VISSR","file","handler","."]
docstr: Get expected area definition.
docstr_tok: ["Get","expected","area","definition","."]
code: def area_def_exp(self, dataset_id):
      """Get expected area definition."""
      if dataset_id["name"] == "IR1":
          resol = 5
          size = 2366
          extent = (-20438.1468, -20438.1468, 20455.4306, 20455.4306)
      else:
          resol = 1
          size = 9464
          extent = (-20444.6235, -20444.6235, 20448.9445, 20448.9445)
      area_id = f"gms-5_vissr_western-pacific_{resol}km"
      desc = f"GMS-5 VISSR Western Pacific area definition with {resol} km resolution"
      return AreaDefinition(
          area_id=area_id,
          description=desc,
          proj_id=area_id,
          projection={
              "a": nav.EARTH_EQUATORIAL_RADIUS,
              "b": nav.EARTH_POLAR_RADIUS,
              "h": "123456",
              "lon_0": "140",
              "no_defs": "None",
              "proj": "geos",
              "type": "crs",
              "units": "m",
              "x_0": "0",
              "y_0": "0",
          },
          area_extent=extent,
          width=size,
          height=size,
      )
  
imports: import datetime
  import gzip
  import fsspec
  import numpy
  import pytest
  import xarray
  from pyresample.geometry import AreaDefinition
  import satpy.tests.reader_tests.gms.test_gms5_vissr_data
  from satpy.readers import FSFile
  from satpy.tests.reader_tests.utils import get_jit_methods, skip_numba_unstable_if_missing
  from satpy.tests.utils import make_dataid
label_desc: Use image node_id 34 for calling the TestFileHandler obj's underlying member method code with example usage: obj.area_def_exp(dataset_id) and returns: AreaDefinition