jetstream: enabled
accounts: {
    A: {
        users: [ {user: a, password: a} ]
        jetstream: enabled
        exports: [
            {service: '$JS.API.>' }
        ]
    },
    I: {
        jetstream: disabled
        users: [ {user: i, password: i} ]
        imports: [
            {service: {account: A, subject: '$JS.API.>'}, to: 'fromA.>' }
        ]
    }
}