*/
GenericUDFOPPlus udf1 = new GenericUDFOPPlus();
GenericUDFOPMinus udf2 = new GenericUDFOPMinus();
GenericUDFOPMultiply udf3 = new GenericUDFOPMultiply();
GenericUDFOPPlus udf4 = new GenericUDFOPPlus();
GenericUDFOPMod udf5 = new GenericUDFOPMod();
ExprNodeGenericFuncDesc sumExpr = new ExprNodeGenericFuncDesc();
sumExpr.setTypeInfo(TypeInfoFactory.intTypeInfo);
sumExpr.setGenericUDF(udf1);
ExprNodeGenericFuncDesc minusExpr = new ExprNodeGenericFuncDesc();