code: def test_unique_elements_in_list():
      """Tests unique_elements_in_list"""
      items = []
      assert unique_elements_in_list(items) == []
  
      items = ["a"]
      assert unique_elements_in_list(items) == ["a"]
  
      items = ["a", "b", "c", "b", "a"]
      assert unique_elements_in_list(items) == ["a", "b", "c"]
  
      items = ["c", "a", "e", "b", "d", "a"]
      assert unique_elements_in_list(items) == ["c", "a", "e", "b", "d"]
  
imports: import warnings
  from dataclasses import dataclass
  from typing import List
  import numpy
  import pandas
  import pytest
  import scipy
  from greykite.common import constants
  from greykite.common.evaluation import ElementwiseEvaluationMetricEnum
  from greykite.common.python_utils import apply_func_to_columns
  from greykite.common.python_utils import assert_equal
  from greykite.common.python_utils import dictionaries_values_to_lists
  from greykite.common.python_utils import dictionary_values_to_lists
  from greykite.common.python_utils import flatten_list
  from greykite.common.python_utils import get_integer
  from greykite.common.python_utils import get_pattern_cols
  from greykite.common.python_utils import group_strs_with_regex_patterns
  from greykite.common.python_utils import ignore_warnings
  from greykite.common.python_utils import mutable_field
  from greykite.common.python_utils import reorder_columns
  from greykite.common.python_utils import split_offset_str
  from greykite.common.python_utils import unique_dict_in_list
  from greykite.common.python_utils import unique_elements_in_list
  from greykite.common.python_utils import unique_in_list
  from greykite.common.python_utils import update_dictionaries
  from greykite.common.python_utils import update_dictionary
label_desc: Use image node_id 3 for calling a global function with example usage: test_unique_elements_in_list() without return types