code: def test_highlight_minmax_nulls(f, axis):
      # GH 42750
      expected = {
          (1, 0): [("background-color", "yellow")],
          (1, 1): [("background-color", "yellow")],
      }
      if axis == 1:
          expected.update({(2, 1): [("background-color", "yellow")]})
  
      if f == "highlight_max":
          df = DataFrame({"a": [NA, 1, None], "b": [np.nan, 1, -1]})
      else:
          df = DataFrame({"a": [NA, -1, None], "b": [np.nan, -1, 1]})
  
      result = getattr(df.style, f)(axis=axis)._compute().ctx
      assert result == expected
  
file_path: pandas/pandas/tests/io/formats/style/test_highlight.py
imports: import numpy
  import pytest
  from pandas import NA, DataFrame, IndexSlice
  from pandas.io.formats.style import Styler
label_desc: Use image node_id 7 for calling a global function with example usage: test_highlight_minmax_nulls(f, axis) without return types