Example: Server-side Skeletom
A server-side skeleton, here called _sk_Count, plays similar role to the client stub but at the server side, i.e. handles remote method invocation
Skeleton implements Count in terms of the generic exec method of the CORBA.Object
exec is called with the methodId value that uniquely identifies a given method
exec is implemented as a switch which jumps to the appropriate method implementation
the actual method execution is performed by CountImpl instance, here passed as _self argument