protected List<Operation> addPreOperations(final Operation<?,?> previousOp,final Operation<?,?> currentOp){
  if (doesOperationNeedValidating(previousOp,currentOp)) {
    return Collections.singletonList((Operation)createValidateOperation((Validatable<?>)currentOp));
  }
  return Collections.emptyList();
}

protected List < Operation > addPreOperations ( final Operation < ? , ? > previousOp , final Operation < ? , ? > currentOp ) { if ( doesOperationNeedValidating ( previousOp , currentOp ) ) { return Collections . singletonList ( ( Operation ) createValidateOperation ( ( Validatable < ? > ) currentOp ) ) ; } return Collections . emptyList ( ) ; }
adds validation operations for any validatable operations .
