protected void onSuccessfulAuthentication(
            final ServerCall<?, ?> call,
            final Metadata headers,
            final Authentication authentication) {
        // Overwrite to add custom behavior.
    }
Hook that will be called on successful authentication. Implementations may only use the call instance in a
non-disruptive manor, that is accessing call attributes or the call descriptor. Implementations must not pollute
the current thread/context with any call-related state, including authentication, beyond the duration of the
method invocation. At the time of calling both the grpc context and the security context have been updated to
reflect the state of the authentication and thus don't have to be setup manually.

<p>
<b>Note:</b> This method is called regardless of whether the authenticated user is authorized or not to perform
the requested action.
</p>

<p>
By default, this method does nothing.
</p>

@param call The call instance to receive response messages.
@param headers The headers associated with the call.
@param authentication The successful authentication instance.
grpc-server-spring-boot-starter/src/main/java/net/devh/boot/grpc/server/security/interceptors/DefaultAuthenticatingServerInterceptor.java