Inject manager to DataType if it's ManagerAware.
Rename Kallable -> Callback.
Rename 'Plugin' to 'DataType'
Manager: Use correct exception
Manager: Do not inject input if it's null.
ItemList is ManagerAware
Mapping data type is ManagerAware.
ItemList is ManagerAware (continue)
Rename 'Plugin' to 'DataType' (continue)
Update test cases.