A basic interface that needs to be implemented by the client-side logic of the notary plugin. This interface has a single method called call which contains the main logic for the client. The client flow must implement this interface in order for it to be instantiated in the provider. If the client flow doesn't implement this interface, the plugin selection will not work. Implementations must:

• Specify the InitiatingFlow annotation.
• Provide a constructor which takes exactly two arguments: a UtxoSignedTransaction representing the transaction, and a > MemberX500Name which is populated with the notary virtual node representing the notary service.
• The call method must specify the Suspendable annotation.

The server side will not have an interface like the client, it will only implement the ResponderFlow interface.

For an example client and server implementation, please refer to the non-validating notary plugin under the `notary-plugins/notary-plugin-non-validating` module in the `corda-runtime-os` repository, or to the quick start guide.