code: def test_append_to_an_enum() -> None:
      s = pl.Series(
          [None, "a", "b", "c"], dtype=pl.Enum(["a", "b", "c"])
      )
      s2 = pl.Series(
          ["c", "a", "b", "c"], dtype=pl.Enum(["a", "b", "c"])
      )
      s.append(s2)
      assert s.len() == 8
  
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 15 for calling a global function with example usage: test_append_to_an_enum() without return types