com.atlassian.jira.upgrade
Interfaces 
BuildVersionRegistry
BuildVersionRegistry.BuildVersion
ConsistencyChecker
UpgradeHistoryItem
UpgradeManager
UpgradeTask
Classes 
AbstractUpgradeTask
BuildNumComparator
BuildVersionImpl
ConnectionKeeper
ConsistencyCheckImpl
DefaultBuildVersionRegistry
LogEvent
PluginSystemLauncher
PluginUpgradeLauncher
UpgradeHistoryItemImpl
UpgradeLauncher
UpgradeManagerImpl
UpgradeTask.Status