| Used to hold the ID of the Flow that is governing the current request
cycle. We cannot use a simple String since this would break the reference
chain when it was assigned to.
The value of the held String is set when the relevant FlowActionProxyBean
is sent the "start" message, and it will be persisted across the flow
by the normal means of the StatePreservationManager, using whatever
Strategy is specified for this bean.
The value of the string is READ by the ARIResolver which will return
a suitably initialised FlowLite ARI when requested.
//TODO: Think more carefully about any other beans which may be time-dependent
WRT. state restoration.
author:
Antranig Basman (antranig@caret.cam.ac.uk) | 