Bug 211839 String grouping unit type needs to support interval range.
Build ID: I20071101-2000 As Chart has supported, the String grouping unit type can be set interval range, the interval range means that the string group will base on row count distinction. For instance, let's say we have a,b,c,d,e,f,g , and set interval range to 2, the grouping result should be a,c,e,g. Now it is a requirement that DtE support the grouping type.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/ResultSetPopulator.java
{
	
	private ResultSetCache smartCache;
	
	private IExpressionProcessor exprProcessor = null;
	
	private BaseQuery query;
	
	private IResultClass rsMeta;
	/**
	 * the IResultIterator instance to which the final populated ResultSet is
	 * output
	 */
	private CachedResultSet ri;
	/**
	 * the instance of GroupProcessorManager, which is used to do group-related
	 * jobs.
	 */
	private GroupProcessorManager groupProcessorManager;
	/**
	 * 
	 */
	private IEventHandler eventHandler;
	
	private DataEngineSession session;
	/**
	 * 
	 * @param query
	 * @param rsMeta