The wallet can handle a lack of connectivity. This could allow the use of the wallet library in an offline way.
Such uses case would be to generate a bunch of addresses that you could manually import into a database (for rolling incomming addresses)
You also have ways to import a known address, transaction, account or any type of data that you could wish to have via the network.
And thus allowing you to use the wallet-library without connectivity.
See here sample code
See here sample code
- From Mnemonic: sample code
- From PrivateKey: sample code