code: def setup(app):
      ''' Required Sphinx extension setup function. '''
      app.add_role('bokeh-commit', bokeh_commit)
      app.add_role('bokeh-issue', bokeh_issue)
      app.add_role('bokeh-pull', bokeh_pull)
      app.add_role('bokeh-tree', bokeh_treef setup(app):
      ''' Required Sphinx extension setup function. '''
      app.add_role('bokeh-commit', bokeh_commit)
      app.add_role('bokeh-issue', bokeh_issue)
      app.add_role('bokeh-pull', bokeh_pull)
      app.add_role('bokeh-tree', bokeh_tree)
docs: Required Sphinx extension setup function.