presentationStop( [id] )
    Stops a REPL presentation.

    If provided a presentation identifier, the corresponding presentation is
    stopped. Otherwise, assuming the command is invoked in a presentation
    workspace, the current presentation is stopped.

    When stopping a REPL presentation, the presentation's REPL workspace is
    both cleared and deleted.

    Parameters
    ----------
    id: number|string (optional)
        Presentation identifier. Must be provided if not currently in a
        presentation workspace.

    Returns
    -------
    bool: boolean
        Boolean indicating whether the REPL successfully stopped a REPL
        presentation.

    Examples
    --------
    > var id = presentationStart( 'beep\n---\nboop\n' );
    > presentationStop();

    See Also
    --------
    presentationStart, workspace, workspaces