code: def test_equality_missing_enum_scalar() -> None:
      dtype = pl.Enum(["a", "b", "c"])
      df = pl.DataFrame(
          {"a": pl.Series([None, "a", "b", "c"], dtype=dtype)}
      )
  
      out = df.select(
          pl.col("a").eq_missing(pl.lit("c", dtype=dtype)).alias("cmp")
      ).get_column("cmp")
      expected = pl.Series(
          "cmp", [False, False, False, True], dtype=pl.Boolean
      )
      assert_series_equal(out, expected)
  
      out_str = df.select(
          pl.col("a").eq_missing(pl.lit("c")).alias("cmp")
      ).get_column("cmp")
      assert_series_equal(out_str, expected)
  
      out = df.select(
          pl.col("a").ne_missing(pl.lit("c", dtype=dtype)).alias("cmp")
      ).get_column("cmp")
      expected = pl.Series(
          "cmp", [True, True, True, False], dtype=pl.Boolean
      )
      assert_series_equal(out, expected)
  
      out_str = df.select(
          pl.col("a").ne_missing(pl.lit("c")).alias("cmp")
      ).get_column("cmp")
      assert_series_equal(out_str, expected)
  
imports: import operator
  from datetime import date
  from textwrap import dedent
  from typing import Any, Callable
  import pytest
  import polars
  from polars import StringCache
  from polars.testing import assert_series_equal
label_desc: Use image node_id 21 for calling a global function with example usage: test_equality_missing_enum_scalar() without return types