/\*\*

- # The state subsystem
-
- This subsystem implements the ui-router state tree
-
- - The [[StateService]] has state-related service methods such as:
- - [[StateService.get]]: Get a registered [[StateDeclaration]] object
- - [[StateService.go]]: Transition from the current state to a new state
- - [[StateService.reload]]: Reload the current state
- - [[StateService.target]]: Get a [[TargetState]] (useful when redirecting from a Transition Hook)
- - [[StateService.onInvalid]]: Register a callback for when a transition to an invalid state is started
- - [[StateService.defaultErrorHandler]]: Register a global callback for when a transition errors
- - The [[StateDeclaration]] interface defines the shape of a state declaration
- - The [[StateRegistry]] contains all the registered states
- - States can be added/removed using the [[StateRegistry.register]] and [[StateRegistry.deregister]]
-     - Note: Bootstrap state registration differs by front-end framework.
- - Get notified of state registration/deregistration using [[StateRegistry.onStatesChanged]].
-
- @packageDocumentation
  \*/
