Bug 145022 Provide a utility method to help GUI enhance aggregate on.
DtE will provide a method hasAggregation(String expression) in org.eclipse.birt.core.data.ExpressionUtil, and the return value will be true when the expression is a valid JS expression and it has aggregation defined.
core/org.eclipse.birt.core/src/org/eclipse/birt/core/data/ExpressionUtil.java
* Return a dataSetRow expression text according to given row name.
	 * 
	 * @param rowName
	 * @return
	 */
	public static String createDataSetRowExpression( String rowName )
	{
		return DATASET_ROW_INDICATOR + "[\"" + rowName + "\"]";
	}
	/**
	 * Return a row expression text according to given row index, which is
	 * 1-based.
	 * 
	 * @param index
	 * @return
	 * @deprecated
	 */
	public static String createRowExpression( int index )
	{
		return ROW_INDICATOR + "[" + index + "]";
	}
	/**
     * extract all column expression info excluding outer_level > 0
	 * @param oldExpression
	 * @return
	 * @throws BirtException
	 */
	public static List extractColumnExpressions( String oldExpression )
			throws BirtException
	{