code: def test_clines_index(clines, exp, env):
      df = DataFrame([[1], [2], [3], [4]])
      result = df.style.to_latex(clines=clines, environment=env)
      expected = f"""\
  0 & 1 \\\\{exp}
  1 & 2 \\\\{exp}
  2 & 3 \\\\{exp}
  3 & 4 \\\\{exp}
  """
      assert expected in result
  
imports: from textwrap import dedent
  import numpy
  import pytest
  from pandas import DataFrame, MultiIndex, Series, option_context
  from pandas.io.formats.style import Styler
  from pandas.io.formats.style_render import _parse_latex_cell_styles, _parse_latex_css_conversion, _parse_latex_header_span, _parse_latex_table_styles, _parse_latex_table_wrapping
label_desc: Use image node_id 50 for calling a global function with example usage: test_clines_index(clines, exp, env) without return types