def service_id(id):
def l(func):<EOL><INDENT>func.__service_id__ = id<EOL>return func<EOL><DEDENT>return l<EOL>
Specifies the service ID to enable re-publishing to the same end point.
Can be applied to the function which is being published:

@publish(...)
@service_id('e5dd3903-796f-4544-b7aa-f4e08b2cc639')
def myfunc():
    return 42

When the function is published it will replace any existing instances of the 
function.