Gets the relevant CPO class that distinguishes between steps in a CPO's
lifecycle.
There is a fundamental distinction between CPO objects
and CPOTrained objects, the latter of which can provide either
retrafo or inverter functionality, or both. CPOTrained are subclassed into
CPOInverter (only inverter functionality), or
CPORetrafo (retrafo, possibly also inverter). To get more information
about a CPORetrafo object's capabilities, use getCPOTrainedCapability.
getCPOClass(cpo)[CPOConstructor | CPO | CPOTrained]
The CPO.
[character(1)]. “CPOConstructor” if the given object is a CPOConstructor,
  “CPO” for a CPO,
  “CPOInverter” for a CPOInverter only,
  “CPORetrafo” for a CPORetrafo object (which may have inverter capabilities, see
  link{getCPOTrainedCapability}),
  “NULLCPO” for a NULLCPO.
Other getters and setters: CPO,
  getCPOAffect,
  getCPOConstructor, getCPOId,
  getCPOName,
  getCPOOperatingType,
  getCPOPredictType,
  getCPOProperties,
  getCPOTrainedCPO,
  getCPOTrainedCapability,
  setCPOId
Other retrafo related: CPOTrained,
  NULLCPO, %>>%,
  applyCPO, as.list.CPO,
  clearRI, getCPOName,
  getCPOOperatingType,
  getCPOPredictType,
  getCPOProperties,
  getCPOTrainedCPO,
  getCPOTrainedCapability,
  getCPOTrainedState,
  is.retrafo,
  makeCPOTrainedFromState,
  pipeCPO, print.CPOConstructor
Other inverter related: CPOTrained,
  NULLCPO, %>>%,
  applyCPO, as.list.CPO,
  clearRI, getCPOName,
  getCPOOperatingType,
  getCPOPredictType,
  getCPOProperties,
  getCPOTrainedCPO,
  getCPOTrainedCapability,
  getCPOTrainedState,
  is.inverter,
  makeCPOTrainedFromState,
  pipeCPO, print.CPOConstructor
Other CPOConstructor related: CPOConstructor,
  getCPOConstructor,
  getCPOName, identicalCPO,
  makeCPO, print.CPOConstructor
Other CPO classifications: CPO,
  getCPOOperatingType,
  getCPOTrainedCapability
Other CPO lifecycle related: CPOConstructor,
  CPOLearner, CPOTrained,
  CPO, NULLCPO,
  %>>%, attachCPO,
  composeCPO,
  getCPOConstructor,
  getCPOTrainedCPO,
  identicalCPO, makeCPO