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/impl/DataPackageImpl.java
* <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public EClass getBaseSampleData( )
	{
		return baseSampleDataEClass;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public EAttribute getBaseSampleData_DataSetRepresentation( )
	{
		return (EAttribute) baseSampleDataEClass.getEStructuralFeatures( )
				.get( 0 );
	}
	/**
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @generated
	 */
	public EClass getBubbleDataSet( )
	{
		return bubbleDataSetEClass;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public EClass getDataElement( )