Open a browser displaying this session.

        Args:
            obj (LayoutDOM object, optional) : a Layout (Row/Column),
                Plot or Widget object to display. The object will be added
                to the session's document.

            browser (str, optional) : browser to show with (default: None)
                For systems that support it, the **browser** argument allows
                specifying which browser to display in, e.g. "safari", "firefox",
                "opera", "windows-default" (see the ``webbrowser`` module
                documentation in the standard lib for more details).

            new (str, optional) : new file output mode (default: "tab")
                For file-based output, opens or raises the browser window
                showing the current output file.  If **new** is 'tab', then
                opens a new tab. If **new** is 'window', then opens a new window.

def show(self, obj=None, browser=None, new="tab"):
        ''' Open a browser displaying this session.

        Args:
            obj (LayoutDOM object, optional) : a Layout (Row/Column),
                Plot or Widget object to display. The object will be added
                to the session's document.

            browser (str, optional) : browser to show with (default: None)
                For systems that support it, the **browser** argument allows
                specifying which browser to display in, e.g. "safari", "firefox",
                "opera", "windows-default" (see the ``webbrowser`` module
                documentation in the standard lib for more details).

            new (str, optional) : new file output mode (default: "tab")
                For file-based output, opens or raises the browser window
                showing the current output file.  If **new** is 'tab', then
                opens a new tab. If **new** is 'window', then opens a new window.

        '''
        if obj and obj not in self.document.roots:
            self.document.add_root(obj)
        show_session(session=self, browser=browser, new=new)