Bug 163271 Cascading parameter dialog - Changing from multiple to single dataset does not work
Steps to reproduce - - Create a new cascading parameter group - Select multiple dataset - define parameter country and associate it with datasetCountry - define parameter state and associate with datasetSate Now try to change from multiple dataset to single dataset. The second dataset still shows up and also the report design file is wrong. The single dataset should be saved ast he cascading parameter group level.
engine/org.eclipse.birt.report.engine.tests/test/org/eclipse/birt/report/engine/api/GetParameterDefinitionTaskTest.java
{
	protected IReportEngine engine = null;
	protected IReportRunnable runnable = null;
	protected IGetParameterDefinitionTask gpdTask = null;
	protected IScalarParameterDefn scalarParam = null;
	static final String REPORT_DESIGN_RESOURCE = "org/eclipse/birt/report/engine/api/GetParameterDefinitionTaskTest.rptdesign";
	static final String REPORT_DESIGN = "GetParameterDefinitionTaskTest.rptdesign";
	public void setUp( ) throws Exception
	{
		removeFile( REPORT_DESIGN );
		copyResource( REPORT_DESIGN_RESOURCE, REPORT_DESIGN );
		engine = createReportEngine( );
		runnable = engine.openReportDesign( REPORT_DESIGN );
		gpdTask = engine.createGetParameterDefinitionTask( runnable );
	}
	public void tearDown( )
	{
		
		if( engine != null )
		{
			engine.shutdown( );
		}
		removeFile( REPORT_DESIGN );
	}
	/**
	 * API test on IScalarParameterDefn.getDefaultValue( ) method Get the
	 * default values of several types of parameters:
	 * <li>String</li>
	 * <li>Boolean</li>
	 * <li>Static List</li>