Xmlrpc server/client

Hello, can anyone explain to me exactly how the XMLPRC SERVER/CLIENT
BLOCK works in GNURADIO. I have tried to google it but still dont quite
understand it. From what I got from google, its used for applications to
communicate with one another locally or on remote devices. In this case
in GNU Radio Im assusming it gives the user control of the run, start,
stop, and wait functions of their flowgraph. However, If I have a XMLRPC
SERVER block on one flowgrpah and the XMLRPC CLient on another
flowgraph, how can I get them to work the way the block is supposed to
function. Any help with be appreciated thanks.