Tests that multiple sessions share the context.
Assigning in 1
Evaluating in 2
{
    id : <messageId>
    result : {
        result : {
            description : 42
            type : number
            value : 42
        }
    }
}
Awaiting in 1
Resolving in 2
Should resolve in 1
{
    id : <messageId>
    result : {
        result : {
            type : string
            value : foo
        }
    }
}