Instances data = new Instances(instances);
if(Utils.eq(data.sumOfWeights(),0))
throw new Exception(" No training data.");
data.deleteWithMissingClass();
if(Utils.eq(data.sumOfWeights(),0))
throw new Exception(" The class labels of all the training data are missing.");
if(data.numInstances() < m_Folds)
throw new Exception(" Not enough data for REP.");