Thanks, James. Currently running in JBoss EAP 7.3.10, among others (not my choice to make,
actually), but this is a more general question. Sounds like I should make a ThreadLocal of
Clients to be safe. Also this is not about universal, formal thread-safety but whether I
can use a once-initialized Client instance, with no configuration changes made further on,
in more than one thread concurrently (typically servlet request threads of the container).