code: def test_enum_creation() -> None:
      s = pl.Series(
          [None, "a", "b"], dtype=pl.Enum(categories=["a", "b"])
      )
      assert s.null_count() == 1
      assert s.len() == 3
      assert s.dtype == pl.Enum(categories=["a", "b"])
  
      # from iterables
      e = pl.Enum(f"x{i}" for i in range(5))
      assert e.categories == ["x0", "x1", "x2", "x3", "x4"]
  
      e = pl.Enum("abcde")
      assert e.categories == ["a", "b", "c", "d", "e"]
  
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 1 for calling a global function with example usage: test_enum_creation() without return types