code: def test_graph_op_edge_color_colorbar(self):
      edges = [(0, 1, 2), (0, 2, 0.5), (1, 3, 3)]
      graph = Graph(edges, vdims="color").opts(
          edge_color="color", colorbar=True
      )
      plot = bokeh_renderer.get_plot(graph)
      assert "edge_color_colorbar" in plot.handles
      assert (
          plot.handles["edge_color_colorbar"].color_mapper
          is plot.handles["edge_color_color_mapper"]
      )
  
imports: import numpy
  from bokeh.models import EdgesAndLinkedNodes, NodesAndLinkedEdges, NodesOnly, Patches
  from bokeh.models.mappers import CategoricalColorMapper, LinearColorMapper
  from holoviews.core.data import Dataset
  from holoviews.element import Chord, Graph, Nodes, TriMesh, VLine, circular_layout
  from holoviews.plotting.bokeh.util import property_to_dict
  from holoviews.util.transform import dim
  from .test_plot import TestBokehPlot, bokeh_renderer
label_desc: Use image node_id 25 for calling the TestBokehGraphPlot obj's underlying member method code with example usage: obj.test_graph_op_edge_color_colorbar() without return types