CLASS rx net/minecraft/migration/MigrationHandlerBuilder
	METHOD a build ()Lrw;
	METHOD a upgradeStack (Lrv;Lfy;ILjava/lang/String;)Lfy;
		ARG 0 handler
		ARG 1 tag
		ARG 2 version
		ARG 3 tagKey
	METHOD a registerTagUpgraders (Lrw;)V
		ARG 0 handler
	METHOD b upgradeStackList (Lrv;Lfy;ILjava/lang/String;)Lfy;
		ARG 0 handler
		ARG 1 tag
		ARG 2 version
		ARG 3 tagKey