Bug 202254 Exception is thrown when category values are null and type of X axis is set to DateTime
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/data/util/DataAdapterFactory.java
}
		public Object caseNumberDataSet( NumberDataSet object )
		{
			return createNumberDataSetAdapter( );
		}
		public Object caseOrthogonalSampleData( OrthogonalSampleData object )
		{
			return createOrthogonalSampleDataAdapter( );
		}
		public Object caseQuery( Query object )
		{
			return createQueryAdapter( );
		}
		public Object caseRule( Rule object )
		{
			return createRuleAdapter( );
		}
		public Object caseSampleData( SampleData object )
		{
			return createSampleDataAdapter( );
		}
		public Object caseSeriesDefinition( SeriesDefinition object )
		{
			return createSeriesDefinitionAdapter( );
		}
		public Object caseSeriesGrouping( SeriesGrouping object )
		{
			return createSeriesGroupingAdapter( );
		}
		public Object caseStockDataSet( StockDataSet object )