code: def render_tinymce_init_js(mce_config, callbacks, id_):
      
      if mce_settings.USE_FILEBROWSER and 'file_browser_callback' not in callbacks:
          callbacks['file_browser_callback'] = 'djangoFileBrowser'
      if mce_settings.USE_SPELLCHECKER and 'spellchecker_callback' not in callbacks:
          callbacks['spellchecker_callback'] = 'tinymce4_spellcheck'
  
      if id_:
          mce_config['selector'] = mce_config.get('selector', 'textarea') + '#{0}'.format(id_)
  
      config = json.dumps(mce_config, cls=DjangoJSONEncoder)[1:-1]
  
      return render_to_string('tinymce/tinymce_init.js',
                              context={'callbacks': callbacks,
                                       'tinymce_config': config,
                                       'is_admin_inline': '__prefix__' in id_})
docs: Renders TinyMCE.init() JavaScript code
  
      :param mce_config: TinyMCE 4 configuration
      :type mce_config: dict
      :param callbacks: TinyMCE callbacks
      :type callbacks: dict
      :param id_: HTML element's ID to which TinyMCE is attached.
      :type id_: str
      :return: TinyMCE.init() code
      :rtype: str