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/IAggregation.java
* is calculated for the whole series of data rows (e.g., the Total.SUM function). Or it can be
     * RUNNING_AGGR, meaning that a value is calculated for each row in the series (e.g., the movingAve function).  
     * @return Type of the aggregation. Value can be SUMMARY_AGGR or RUNNING_AGGR
     */
    public int getType();
 
    /**
     * Gets information about the parameters that this aggregate function takes as an array of boolean values. 
     * <p> 
     * The length of the returned array is the number of runtime parameters that this aggregate function
     * takes. Note that this number excludes the optional filter and group parameters common to all aggregate
     * functions. Those two parameters are handled by the DtE. <p>
     * If the n'th element in the array is true, it means that the n'th parameter is a dynamic parameter 
     * which needs to be evaluated at each row. Otherwise the parameter is static, and it only needs to be
     * evaluated once at the start of the accumulation <p>
     * For example, the Total.movingAve function is defined as <br> 
     * movingAve( expr, window [, filter [, group ]] )<br>
     * The expr parameter is the data being aggregated over and should be calculated at every row. The
     * window parameter on the other hand must be a fixed number for each series of data. Therefore the class
     * implementing the movingAve function should return boolean array [true, false].
     */
     public boolean[] getParameterDefn();
    
     /**
     * Creates a new instance of the accumulator for this aggregation.
     * @return A new instance of the accumulator
     */
     public Accumulator newAccumulator();
}