code: def get_javascript(cls, stream=None):
      if stream is None:
          output = io.StringIO()
      else:
          output = stream
      super().get_javascript(stream=output)
      import pkgutil
  
      data = pkgutil.get_data(
          __package__, "web_backend/js/nbagg_mpl.js"
      ).decode("utf-8")
      output.write(data)
      if stream is None:
          return output.getvalue()
  
imports: from base64 import b64encode
  import io
  import json
  import pathlib
  import uuid
  from ipykernel.comm import Comm
  from IPython.display import display, Javascript, HTML
  from matplotlib import is_interactive
  from matplotlib._pylab_helpers import Gcf
  from matplotlib.backend_bases import _Backend, CloseEvent, NavigationToolbar2
  from .backend_webagg_core import FigureCanvasWebAggCore, FigureManagerWebAgg, NavigationToolbar2WebAgg
  from .backend_webagg_core import TimerTornado, TimerAsyncio
label_desc: Use image node_id 7 for calling the FigureManagerNbAgg obj's underlying member method code with example usage: obj.get_javascript(cls, stream) and returns: output