public List<FuncSpec> getArgToFuncMapping() throws FrontendException {
List<FieldSchema> fields = new ArrayList<FieldSchema>(3);
fields.add(new Schema.FieldSchema(null, DataType.INTEGER));
fields.add(new Schema.FieldSchema(null, DataType.INTEGER));
fields.add(new Schema.FieldSchema(null, DataType.BAG));
FuncSpec funcSpec = new FuncSpec(this.getClass().getName(), new Schema(fields));
List<FuncSpec> funcSpecs = new ArrayList<FuncSpec>(1);
funcSpecs.add(funcSpec);
return funcSpecs;
}