OptionaldataOptionalentitySet this to true if the requested entity data could not be found.
The same behavior behavior is also triggered if data is set to null.
OptionalerrorHolds the error details in case something went wrong while loading.
It allows to pass a StationError object, a simple message (as string) any object.
Indicates whether the data is still loading or not
Holds the data after the loading is finished. Make sure the property is set to
null(default for GraphQL APIs) in case the entity could not be found.