Example: A variable probe
probeMap = [EmptyProbeMap createBegin: self];
[probeMap setProbedClass: [self class]];
probeMap = [probeMap createEnd];
[probeMap addProbe: [probeLibrary
getProbeForVariable: "worldXSize”
[probeLibrary setProbeMap: probeMap
(also must execute CREATE_PROBE_DISPLAY macro