def _checkParams(self):
     UserModificationBase._checkParams(self)
     ConferenceReviewingBase._checkParams(self)
     if self._params.has_key('contributions'):
         pm = ParameterManager(self._params)
         contributionsIds = pm.extract("contributions", pType=list, allowEmpty=False)
         self._contributions = [self._conf.getContributionById(contributionId) for contributionId in contributionsIds]
     else:
         raise ServiceError("ERR-REV2",_("List of contribution ids not set"))

 def _checkParams(self):
     UserModificationBase._checkParams(self)
     ConferenceReviewingBase._checkParams(self)
     if self._params.has_key("contributions"):
         pm = ParameterManager(self._params)
         contributionsIds = {int(c) for c in pm.extract("contributions", pType=list, allowEmpty=False)}
         self._contributions = [contrib for contrib in self._event.contributions if contrib.id in contributionsIds]
     else:
         raise ServiceError("ERR-REV2", _("List of contribution ids not set"))

 def _checkParams(self):
     CollaborationChangePluginManagersBase._checkParams(self)
     UserModificationBase._checkParams(self)

 def _checkParams(self):
     PluginOptionsBase._checkParams(self)
     UserModificationBase._checkParams(self)