code: def test_vmin_vmax(self):
      df = self.world.copy()
      df["range"] = range(len(df))
      m = df.explore("range", vmin=-100, vmax=1000)
      out_str = self._fetch_map_string(m)
      assert (
          'case"176":return{"color":"#3b528b","fillColor":"#3b528b"'
          in out_str
      )
      assert (
          'case"119":return{"color":"#414287","fillColor":"#414287"'
          in out_str
      )
      assert (
          'case"3":return{"color":"#482173","fillColor":"#482173"'
          in out_str
      )
  
      # test 0
      df2 = self.nybb.copy()
      df2["values"] = df2["BoroCode"] * 10.0
      m = df2[df2["values"] >= 30].explore("values", vmin=0)
      out_str = self._fetch_map_string(m)
      if FOLIUM_G_014:
          assert (
              'case"0":return{"color":"#fde725","fillColor":"#fde725"'
              in out_str
          )
          assert (
              'case"1":return{"color":"#7ad151","fillColor":"#7ad151"'
              in out_str
          )
          assert (
              'default:return{"color":"#22a884","fillColor":"#22a884"'
              in out_str
          )
      else:
          assert (
              'case"1":return{"color":"#7ad151","fillColor":"#7ad151"'
              in out_str
          )
          assert (
              'case"2":return{"color":"#22a884","fillColor":"#22a884"'
              in out_str
          )
          assert (
              'default:return{"color":"#fde725","fillColor":"#fde725"'
              in out_str
          )
  
      df2["values_negative"] = df2["BoroCode"] * -10.0
      m = df2[df2["values_negative"] <= 30].explore(
          "values_negative", vmax=0
      )
      out_str = self._fetch_map_string(m)
      assert (
          'case"1":return{"color":"#414487","fillColor":"#414487"'
          in out_str
      )
      assert (
          'case"2":return{"color":"#2a788e","fillColor":"#2a788e"'
          in out_str
      )
  
imports: import geopandas
  import numpy
  import pandas
  import pytest
  import shapely
  from packaging.version import Version
  from matplotlib import cm
  from matplotlib import colors
  from branca.colormap import StepColormap
label_desc: Use image node_id 20 for calling the TestExplore obj's underlying member method code with example usage: obj.test_vmin_vmax() without return types