public static File createMinimalSplit(String inputFolder,
Takes the available CAS and creates more cases from them to conform to the minimal requested
amount of CAS objects to have sufficient for running a cross-validation. Computes a
rule-of-thumb value to split each of the found cas into N sub-cases and the end the total
created number is compared to the requested number of CAS and an exception thrown if too few
CAS were created.
inputFolder - the input folder
numFolds - number of folds to create
numAvailableJCas - number available cas'
isSequence - is sequence model
returns folder with sufficient folds
Exception - if not enough data is available for creating the required number of folds