docstr: Check choropleth colors
docstr_tok: ["Check","choropleth","colors"]
code: def test_choropleth_linear(self):
      """Check choropleth colors"""
      # default cmap
      m = self.nybb.explore(column="Shape_Leng")
      out_str = self._fetch_map_string(m)
      assert 'color":"#440154"' in out_str
      assert 'color":"#fde725"' in out_str
      assert 'color":"#50c46a"' in out_str
      assert 'color":"#481467"' in out_str
      assert 'color":"#3d4e8a"' in out_str
  
      # named cmap
      m = self.nybb.explore(column="Shape_Leng", cmap="PuRd")
      out_str = self._fetch_map_string(m)
      assert 'color":"#f7f4f9"' in out_str
      assert 'color":"#67001f"' in out_str
      assert 'color":"#d31760"' in out_str
      assert 'color":"#f0ecf5"' in out_str
      assert 'color":"#d6bedc"' 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 7 for calling the TestExplore obj's underlying member method code with example usage: obj.test_choropleth_linear() without return types