code: def test_background_gradient_vmin_vmax():
      # GH 12145
      df = DataFrame(range(5))
      ctx = df.style.background_gradient(vmin=1, vmax=3)._compute().ctx
      assert ctx[(0, 0)] == ctx[(1, 0)]
      assert ctx[(4, 0)] == ctx[(3, 0)]
  
imports: import gc
  import numpy
  import pytest
  from pandas import DataFrame, IndexSlice, Series
  import matplotlib
  from pandas.io.formats.style import Styler
label_desc: Use image node_id 10 for calling a global function with example usage: test_background_gradient_vmin_vmax() without return types