Filtered method invocation

We discuss modifications made to normal MICO method invocation sequence in order to incorporate the filtering functionality. First important modification to invocation sequence is creation of a specialized FilterServerRequest instead of StaticServerRequest in make_request() method. The responsibilities of server-side filter request object include method name translation and performing upfiltering and downfiltering. To satisfy these responsibilities, it overrides three methods viz. op_name(), read_args() and write_results().