Flash with killed darksprite

HiddenMoveHandlers::CanUseMove.add(:FLASH,proc{|move,pkmn,showmsg|
   return false if !pbCheckHiddenMoveBadge(BADGEFORFLASH,showmsg)
   if !pbGetMetadata($game_map.map_id,MetadataDarkMap)
     Kernel.pbMessage(_INTL("Can't use that here.")) if showmsg
     return false
   end
   darkness = $PokemonTemp.darknessSprite
   if !darkness || darkness.disposed? # EDIT
     Kernel.pbMessage(_INTL("It's not dark anymore.")) if showmsg
     return false
   end
   if $PokemonGlobal.flashUsed
     Kernel.pbMessage(_INTL("Flash is already being used.")) if showmsg
     return false
   end
   return true
})