Depending on the platform, this may map to 'Window', 'Function', 'Meta', 'Menu', or 'NumLock'.
Such 'Meta keys' will map to one of META, META2, META3. On X Windows platforms these META values map to the modifier masks Mod1Mask,
Mod2Mask, Mod3Mask, e.g. an event having ATSPI_MODIFIER_META2 means that the 'Mod2Mask' bit is set in the corresponding
XEvent.