The URL used when HTTP requests are performed is defined statically
with the url_prefix passed to the constructor of JsonHttpApiClient
together with the path property in JsonHttpApiFunction.
For applications that require dynamic URLs there is no way to rewrite
the URL. Let's add a mechanism that allows API users to apply custom
URL reqriting rules by adding a reqrite_url method to
JsonHttpApiFunction. API users may then overload this method with a
custom implementation as needed.
Related: SYS#7918
Change-Id: Id2713a867079cc140517fe312189e5e2162608a5
0d891e362d