Bug 123036 Data in a reprot is doubly stored
We currently stored data twice. Once in the content stream, once by DtE. The instance stored by content stream should not be there.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ResultIterator.java
* @param value2
		 * @return
		 */
		private boolean isTwoObjectEqual( Object value1, Object value2 )
		{
			 
			if( value1 instanceof Date && value2 instanceof Date)
				return ((Date)value1).getTime() == ((Date)value2).getTime();
			else
			    return  value1.equals( value2 );
		}
		/**
		 * The method which extracts column name from group definition.
		 * 
		 * @param group
		 * @return
		 */
		private String getGroupKeyColumnName( GroupDefinition group )
		{
			String columnName;
			if ( group.getKeyColumn( ) != null )
			{
				columnName = group.getKeyColumn( );
			}
			else
			{
				columnName = group.getKeyExpression( );
				if ( columnName.trim( ).toUpperCase( ).startsWith( "ROW" ) )
				{
					String temp = columnName.trim( ).substring( 3 ).trim();