title: Interactive Selection on Jupyter Notebook through Select Widget raise "Models must be owned by only a single document" error
body: <p>How can I create an interactive bar plot with bokeh through <a href="https://bokeh.pydata.org/en/latest/docs/user_guide/interaction/widgets.html#select" rel="nofollow noreferrer">a selection widget</a> on Jupyter Notebook?</p>
  
  <p>Why the Notebook raise the following error: </p>
  
  <p><em>"RuntimeError: Models must be owned by only a single document, Title(id='1044', ...) is already in a doc
  ERROR:tornado.access:500 GET /autoload.js?bokeh-autoload-element=1002&amp;bokeh-absolute-url=<a href="http://localhost:54277&amp;resources=none" rel="nofollow noreferrer">http://localhost:54277&amp;resources=none</a> (::1) 117.01ms"</em></p>
  
  <p>I read carefully this example from <a href="https://github.com/bokeh/bokeh/blob/1.0.4/examples/howto/server_embed/notebook_embed.ipynb" rel="nofollow noreferrer">github</a> and this similar situation from a <a href="https://groups.google.com/a/continuum.io/forum/#!topic/bokeh/C1dePl2AZvo" rel="nofollow noreferrer">Google Bokeh Group</a>, in the latter they run a bokeh server not a the jupyter kernel</p>
  
  <pre><code>output_notebook()
  
  dct={'Date' : ["2018-01-07", "2018-01-12", "2018-01-13", "2018-01-14", "2018-01-20", "2018-01-24"],'Activity' : ['A','B','A','B','A','B'],'Count' : [1, 2, 5, 3, 7, 1]}
  df=pd.DataFrame(dct)
  
  activity_list=df['Activity'].unique().tolist().copy()
  activity_selected='A'
  def modify_doc(doc):
       def make_plot(cdf):
           plot = figure()
           plot.vbar(x=cdf.Date, top=cdf.Count, width=0.9)
           push_notebook()
           show(plot, notebook_handle = True)
           return plot
       def update_plot(attr, old, new):
           activity =  select.value
           sdf = df.copy()
           sdf = sdf[sdf['Activity'] == activity]
           layout.children[0] = make_plot(sdf)
  
  
       select = Select(title='Select Activity', value=activity_selected, options=activity_list)
       select.on_change('value', update_plot)
       p=make_plot(df)
       layout=column(select, p)
       doc.add_root(layout)
  show(modify_doc)
  </code></pre>
  
  <p>What I expect is something like this in the snapshoot:</p>
  
  <p><a href="https://i.stack.imgur.com/WSyYi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WSyYi.png" alt="enter image description here"></a></p>
  
  <p>I am using Bokeh 1.0.4</p>