ExpressionOperator input = args.get(i);
OperatorKey newKey = genNewOperatorKey(udf);
LOCast cast = new LOCast(currentPlan, newKey, input, tFSch.type);
currentPlan.add(cast);
try {
currentPlan.insertBetween(input, cast, udf);
this.visit(cast);
} catch (PlanException pe) {
int errCode = 2059;
String msg = "Problem with inserting cast operator for user defined function in plan.";
throw new TypeCheckerException(msg, errCode, PigException.BUG, pe);