text: import pytest
  from amalgama import amalgama
  
  split_before_params = {
      "starts_with_sep": ("xooxoo", [["x", "o", "o"], ["x", "o", "o"]]),
      "ends_with_sep": ("ooxoox", [["o", "o"], ["x", "o", "o"], ["x"]]),
      "no_sep": ("ooo", [["o", "o", "o"]]),
  }
  
  
  @pytest.mark.parametrize("iterable,expected", split_before_params.values(), ids=list(split_before_params.keys()))
  def test_split_before(iterable, expected):
      actual = list(amalgama.split_before(iterable, lambda c: c == "x"))
      assert actual == expected
  