CLASS qw net/minecraft/migration/MigrationHandlerBuilder
	METHOD a build ()Lqv;
	METHOD a upgradeStack (Lqu;Lfc;ILjava/lang/String;)Lfc;
	METHOD a registerTagUpgraders (Lqv;)V
	METHOD b upgradeStackList (Lqu;Lfc;ILjava/lang/String;)Lfc;