code: def test_is_first_distinct() -> None:
      lf = pl.LazyFrame({"a": [4, 1, 4]})
      result = lf.select(pl.col("a").is_first_distinct()).collect()["a"]
      expected = pl.Series("a", [True, True, False])
      assert_series_equal(result, expected)
  
file_path: polars/py-polars/tests/unit/operations/test_is_first_last_distinct.py
imports: import pytest
  import polars
  from polars.testing import assert_frame_equal, assert_series_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_is_first_distinct() without return types