title: How to update the data source for networkx graph with bokeh?
body: <p>I would like to change the data source for bokeh network graph. However the from_network function does not allow me to input source = new_source for example. However do I change the data source for the network graph to be updated if click a button?</p>
  
  <pre><code>#PLOT GRAPH WITH BOKEH SERVER
  def update_plot_layout(layout_name, range, source_bar):
  plot_degree = figure(title='Knowledge Graph', x_range=range, y_range=range,
                tools=['box_select,pan,wheel_zoom,box_zoom,reset'], 
  toolbar_location="right",
                toolbar_sticky=False)
  
  plot_degree.grid.grid_line_color = None
  
  
  graph = from_networkx(g, layout_name , scale=2, center=(0,0))
  # graph.node_renderer.data_source = source
  #
  graph.node_renderer.glyph = Circle(size=20,
                                     fill_color= 'crimson',
                                     fill_alpha = 0.8, line_color = 'black')
  
  # graph.node_renderer.glyph = Circle(size='node_size',
  #                                    fill_color= 'crimson',
  #                                    fill_alpha = 0.8, line_color = 'black')
  #
  graph.edge_renderer.glyph = MultiLine(line_color='gray', line_width=1.5, line_alpha = 0.5)
  
  # plot_degree.add_tools(HoverTool(line_policy='interp', tooltips=[('ID', '@index'),
  #                                 ('Degree Centrallity', '@degree_centrality')]))
  
  plot_degree.renderers.append(graph)
  </code></pre>