Bug 208718 Exception is thrown out when exported data with column's data type [0002]
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ReportEngineService.java
* @param requestInfo
	 * @return list of available column value
	 * @throws BirtException
	 */
	public List getColumnValueSet( String bindingName,
			DesignElementHandle elementHandle, IRequestInfo requestInfo )
			throws BirtException
	{
		if ( bindingName == null || elementHandle == null
				|| !( elementHandle instanceof ReportItemHandle ) )
			return Collections.EMPTY_LIST;
		
		ReportItemHandle reportItem = getBindingHolder( elementHandle );
		if ( reportItem == null )
			return Collections.EMPTY_LIST;
		List selectValueList = new ArrayList( );
		DataRequestSession session = DataRequestSession
				.newSession( new DataSessionContext(
						DataSessionContext.MODE_DIRECT_PRESENTATION, reportItem
								.getModuleHandle( ) ) );
		selectValueList.addAll( session.getColumnValueSet( reportItem
				.getDataSet( ), reportItem.paramBindingsIterator( ), reportItem
				.columnBindingsIterator( ), bindingName, requestInfo ) );
		session.shutdown( );
		return selectValueList;
	}
	/**
	 * Collects all the distinct values for the given element and
	 * bindColumnName. This method will traverse the design tree for the given
	 * element and get the nearest binding column holder of it. The nearest