def test_only_non_unique_elements(): assert non_unique_elements([5, 5, 5, 5, 5]) == [5, 5, 5, 5, 5], "Only non-unique elements"
def test_only_unique_elements(): assert non_unique_elements([1, 2, 3, 4, 5]) == [], "Only unique elements"
def test_list_with_empty_strings(): assert non_unique_elements(["", "", "", "a"]) == ["", "", ""], "List with empty strings"
def test_string(): assert non_unique_elements("aaaagggrty") == [ "a", "a", "a", "a", "g", "g", "g" ], "A string"
def test_empty_string(): assert non_unique_elements("") == [], "Empty string"
def test_dictionary(): assert non_unique_elements({ "first": 1, "second": 1, "third": 3 }) == [1, 1], "Dictionary"
def test_empty_list(): assert non_unique_elements([]) == [], "Empty list"
def test_floats(): assert non_unique_elements([1.1 + 2.2, 3.3]) == [], "Floats"
def test_words(): assert non_unique_elements(["hello", "hello", "world"]) == ["hello", "hello"], "Words"
def test_one_unique_element(): assert non_unique_elements([10, 9, 10, 10, 9, 8]) == [10, 9, 10, 10, 9], "One unique element"