Get the CPOConstructor used to create a CPO or CPOTrained object.
Only primitive CPO or CPOTrained objects have an originating CPOConstructor.
getCPOConstructor(cpo)[CPO | CPOTrained]
The CPO, Retrafo, or Inverter to get the original CPOConstructor from.
[CPOConstructor]. The original CPOConstructor.
Other getters and setters: CPO,
  getCPOAffect, getCPOClass,
  getCPOId, getCPOName,
  getCPOOperatingType,
  getCPOPredictType,
  getCPOProperties,
  getCPOTrainedCPO,
  getCPOTrainedCapability,
  setCPOId
Other CPO lifecycle related: CPOConstructor,
  CPOLearner, CPOTrained,
  CPO, NULLCPO,
  %>>%, attachCPO,
  composeCPO, getCPOClass,
  getCPOTrainedCPO,
  identicalCPO, makeCPO
Other CPOConstructor related: CPOConstructor,
  getCPOClass, getCPOName,
  identicalCPO, makeCPO,
  print.CPOConstructor