code: def test_dual_map():
      m = folium.plugins.DualMap((0, 0))
  
      folium.FeatureGroup(name="both").add_to(m)
      folium.FeatureGroup(name="left").add_to(m.m1)
      folium.FeatureGroup(name="right").add_to(m.m2)
  
      figure = m.get_root()
      assert isinstance(figure, folium.Figure)
      out = normalize(figure.render())
  
      script = '<script src="https://cdn.jsdelivr.net/gh/jieter/Leaflet.Sync/L.Map.Sync.min.js"></script>'  # noqa
      assert script in out
  
      tmpl = Template(
          """
          {{ this.m1.get_name() }}.sync({{ this.m2.get_name() }});
          {{ this.m2.get_name() }}.sync({{ this.m1.get_name() }});
      """
      )
  
      assert normalize(tmpl.render(this=m)) in out
  
imports: from jinja2 import Template
  import folium
  import folium.plugins
  from folium.utilities import normalize
label_desc: Use image node_id 1 for calling a global function with example usage: test_dual_map() without return types