code: def test_isna(NA):
      s2 = GeoSeries(
          [Point(0, 0), NA, Point(2, 2)], index=[2, 4, 5], name="tt"
      )
      exp = pd.Series([False, True, False], index=[2, 4, 5], name="tt")
      res = s2.isnull()
      assert type(res) == pd.Series
      assert_series_equal(res, exp)
      res = s2.isna()
      assert_series_equal(res, exp)
      res = s2.notnull()
      assert_series_equal(res, ~exp)
      res = s2.notna()
      assert_series_equal(res, ~exp)
  
imports: import os
  from packaging.version import Version
  import warnings
  import numpy
  from numpy.testing import assert_array_equal
  import pandas
  import shapely
  from shapely.geometry import Point, GeometryCollection, LineString, LinearRing
  import geopandas
  from geopandas import GeoDataFrame, GeoSeries
  import geopandas._compat
  from geopandas.array import from_shapely
  from geopandas.testing import assert_geodataframe_equal, assert_geoseries_equal
  from pandas.testing import assert_frame_equal, assert_series_equal
  import pytest
label_desc: Use image node_id 26 for calling a global function with example usage: test_isna(NA) without return types