upgrade Directory Reference

Directory dependency graph for upgrade:

Directories
	model

Files
	BlockDataUpgrader.php
	BlockIdMetaUpgrader.php
	BlockStateUpgrader.php
	BlockStateUpgradeSchema.php
	BlockStateUpgradeSchemaBlockRemap.php
	BlockStateUpgradeSchemaFlattenInfo.php
	BlockStateUpgradeSchemaUtils.php
	BlockStateUpgradeSchemaValueRemap.php
	LegacyBlockIdToStringIdMap.php