Bug 123726 "Top n", "Bottom n" in highlight dialog doesn't work.
Description: "Top n", "Bottom n" in highlight dialog doesn't work. Steps to reproduce: 1. Add a highlight for a table. 2. Set highlight rule: "account_id", "top n", "3", let its font color red. 3. Preview the report, it doesn't work. Attached is design file.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/api/aggregation/Accumulator.java
*/
    public void	finish() throws DataException
    {}
    
    /**
     * This method is called on every data row to supply arguments to the aggregation. The args[] argument
     * provides an array of argument values that this aggregation expected. The number of arguments and
     * their types are defined by the Aggregation.getParameterDefn() method. <p>
     * 
     * Each argument can have type java.lang.Integer, java.lang.Double, java.lang.Boolean, java.lang.String, java.util.Date, 
     * java.math.BigDecimal or java.sql.Blob. It can also be null. <p>
     * If an argument is not of an expected type (e.g., a String is passed in to a SUM 
     * accumulator), the method should make reasonable efforts to convert the argument to its expected
     * type. If no reasonable conversion can be made, this method may throw an RuntimeException or its
     * subclass to indicate such an error.<p>
     * @param rowValue 	Argument to the aggregate function calculated based on current data row. 
     * @throws DataException data type conversion will throw <code>DteException</code>
     */
    abstract public void onRow( Object[] args ) throws DataException;
    
    /**
     * This method is called after the finish() method to obtain the aggregate value. The return value
     * can be of class   java.lang.Integer, java.lang.Double, java.lang.Boolean, java.lang.String, java.util.Date, 
     * java.math.BigDecimal or java.sql.Blob. Or it can be null to indicate a null aggregate value.
     * @return Aggregate value calculated over the processed rows  
     */
    abstract public Object getValue();
    
}