userspace(pid=9765,slow_path())
userspace(pid=9765,slow_path(cfm))
userspace(pid=9765,slow_path(cfm,match))
-userspace(pid=9123,userdata=0x815309)
userspace(pid=1234567,userdata(0102030405060708090a0b0c0d0e0f))
+userspace(pid=6633,flow_sample(probability=123,collector_set_id=1234,obs_domain_id=2345,obs_point_id=3456))
+userspace(pid=6633,ipfix)
set(in_port(2))
set(eth(src=00:01:02:03:04:05,dst=10:11:12:13:14:15))
set(eth_type(0x1234))