[Multiplot Error] Not able to run the multiplot visualization example

[sara-02]

Describe the bug
While running the Multiplot visualization example in the tutorial, I am getting the following error.

---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
<ipython-input-6-a6f8d12c6bbd> in <module>
      4 vm.add_plot(p2)
      5 m = vm.plot()
----> 6 show(m)

/usr/local/lib/python3.6/dist-packages/bokeh/io/showing.py in show(obj, browser, new, notebook_handle, notebook_url, **kw)
    137         return run_notebook_hook(state.notebook_type, 'app', obj, state, notebook_url, **kw)
    138 
--> 139     return _show_with_state(obj, state, browser, new, notebook_handle=notebook_handle)
    140 
    141 #-----------------------------------------------------------------------------

/usr/local/lib/python3.6/dist-packages/bokeh/io/showing.py in _show_with_state(obj, state, browser, new, notebook_handle)
    175 
    176     if state.file or not shown:
--> 177         _show_file_with_state(obj, state, new, controller)
    178 
    179     return comms_handle

/usr/local/lib/python3.6/dist-packages/bokeh/io/showing.py in _show_file_with_state(obj, state, new, controller)
    158 
    159     '''
--> 160     filename = save(obj, state=state)
    161     controller.open("file://" + filename, new=NEW_PARAM[new])
    162 

/usr/local/lib/python3.6/dist-packages/bokeh/io/saving.py in save(obj, filename, resources, title, template, state, **kwargs)
     83 
     84     filename, resources, title = _get_save_args(state, filename, resources, title)
---> 85     _save_helper(obj, filename, resources, title, template)
     86     return abspath(filename)
     87 

/usr/local/lib/python3.6/dist-packages/bokeh/io/saving.py in _save_helper(obj, filename, resources, title, template)
    145     '''
    146     from ..embed import file_html
--> 147     html = file_html(obj, resources, title=title, template=template)
    148 
    149     with io.open(filename, mode="w", encoding="utf-8") as f:

/usr/local/lib/python3.6/dist-packages/bokeh/embed/standalone.py in file_html(models, resources, title, template, template_variables, theme, suppress_callback_warning, _always_new)
    301         models_seq = models
    302 
--> 303     with OutputDocumentFor(models_seq, apply_theme=theme, always_new=_always_new) as doc:
    304         (docs_json, render_items) = standalone_docs_json_and_render_items(models_seq, suppress_callback_warning=suppress_callback_warning)
    305         title = _title_from_models(models_seq, title)

/usr/lib/python3.6/contextlib.py in __enter__(self)
     79     def __enter__(self):
     80         try:
---> 81             return next(self.gen)
     82         except StopIteration:
     83             raise RuntimeError("generator didn't yield") from None

/usr/local/lib/python3.6/dist-packages/bokeh/embed/util.py in OutputDocumentFor(objs, apply_theme, always_new)
    132             doc = Document()
    133             for model in objs:
--> 134                 doc.add_root(model)
    135 
    136         # handle a single shared document

/usr/local/lib/python3.6/dist-packages/bokeh/document/document.py in add_root(self, model, setter)
    317             self._roots.append(model)
    318         finally:
--> 319             self._pop_all_models_freeze()
    320         self._trigger_on_change(RootAddedEvent(self, model, setter))
    321 

/usr/local/lib/python3.6/dist-packages/bokeh/document/document.py in _pop_all_models_freeze(self)
   1054         self._all_models_freeze_count -= 1
   1055         if self._all_models_freeze_count == 0:
-> 1056             self._recompute_all_models()
   1057 
   1058     def _recompute_all_models(self):

/usr/local/lib/python3.6/dist-packages/bokeh/document/document.py in _recompute_all_models(self)
   1077             d._detach_document()
   1078         for a in to_attach:
-> 1079             a._attach_document(self)
   1080         self._all_models = recomputed
   1081         self._all_models_by_name = recomputed_by_name

/usr/local/lib/python3.6/dist-packages/bokeh/model.py in _attach_document(self, doc)
    669         '''
    670         if self._document is not None and self._document is not doc:
--> 671             raise RuntimeError("Models must be owned by only a single document, %r is already in a doc" % (self))
    672         doc.theme.apply_to_model(self)
    673         self._document = doc

RuntimeError: Models must be owned by only a single document, BoxZoomTool(id='1020', ...) is already in a doc

To Reproduce
Steps to reproduce the behavior:

• NDlib version: 5.0.2
• Operating System: Linux
• Python version: 3.6
• Bokeh: 2.0.2
  Sample code that is giving the error:

from ndlib.viz.bokeh.MultiPlot import MultiPlot
vm = MultiPlot()
vm.add_plot(p)
vm.add_plot(p2)
m = vm.plot()
show(m)

The code is present under: Tutorial

Expected behavior
We should be able to generate the bokeh plot.