val Firebase.database: FirebaseDatabase
Returns the FirebaseDatabase instance of the default FirebaseApp.
fun Firebase.database(url: String): FirebaseDatabase
Returns the FirebaseDatabase instance for the specified url.
fun Firebase.database(app: FirebaseApp): FirebaseDatabase
Returns the FirebaseDatabase instance of the given FirebaseApp.
fun Firebase.database( app: FirebaseApp, url: String): FirebaseDatabase
Returns the FirebaseDatabase instance of the given FirebaseApp and url.