method returns object reference

[Ian Kelly]

On Tue, Jun 23, 2015 at 12:32 PM, Tim <jtim.arnold at gmail.com> wrote:
> The code below prints the following two lines, showing how the 'newkey' is now inside the Client response, even though it was set in the worker.  This must be bad practice!  In my real code, the response is no longer an instance variable, which fixed the problem. It never had any business being bound to the client anyway.

I agree. There may be reasons why the client would want to hold onto
the response, e.g. caching, but there are none evident in the code you
posted. What it *shouldn't* do if it's going to hold on to state like
that is share it with external code without at least a contract
defining allowed mutations. If the consumer can't reasonably be
expected not to modify the shared state, then it should be copied, not
shared.