Alt key

1:
Default settings.
Add a snippet. Assign Alt+Shift+; to its Shortcut.
Duplicate the snippet. (So when you press Alt+Shift+; you get a menu.)
Assign Alt+; to “Split Lines” command.
Select a wrapped line.
Press Alt+Shift+;
Press Alt key to close the menu.
** This will trigger Alt+; (“Split Lines” command).

Press Alt+Shift+;
Press Esc key to close the menu.
** It gives a sound (“Default Beep” in the system sound scheme).

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2:
Default settings.
Press Alt key once. (The menu bar is focused.)
Press any Alt+ shortcut key (e.g. Alt+F3).
Now it seems the menu bar is not focused.
** But I have to press Alt key twice to focus the menu bar.