    @Test
    public void testSchema() throws Exception {

        // No type
        Over func = new Over();
        Schema in = Schema.generateNestedSchema(DataType.BAG, DataType.INTEGER);
        Schema out = func.outputSchema(in);
        assertEquals("{{NULL}}", out.toString());

        // chararray
        func = new Over("chararray");
        in = Schema.generateNestedSchema(DataType.BAG, DataType.INTEGER);
        out = func.outputSchema(in);
        assertEquals("{org.apache.pig.piggybank.evaluation.over_1: {result: chararray}}", out.toString());

        // int
        func = new Over("Int");
        in = Schema.generateNestedSchema(DataType.BAG, DataType.INTEGER);
        out = func.outputSchema(in);
        assertEquals("{org.apache.pig.piggybank.evaluation.over_2: {result: int}}", out.toString());

        // double
        func = new Over("DOUBLE");
        in = Schema.generateNestedSchema(DataType.BAG, DataType.INTEGER);
        out = func.outputSchema(in);
        assertEquals("{org.apache.pig.piggybank.evaluation.over_3: {result: double}}", out.toString());

        // named 
        func = new Over("bob:chararray");
        in = Schema.generateNestedSchema(DataType.BAG, DataType.INTEGER);
        out = func.outputSchema(in);
        assertEquals("{org.apache.pig.piggybank.evaluation.over_4: {bob: chararray}}", out.toString());
    }