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/DataFactory.java
* @generated
	 */
	Action createAction( );
	/**
	 * Returns a new object of class '<em>Base Sample Data</em>'.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @return a new object of class '<em>Base Sample Data</em>'.
	 * @generated
	 */
	BaseSampleData createBaseSampleData( );
	/**
	 * Returns a new object of class '<em>Bubble Data Set</em>'.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @return a new object of class '<em>Bubble Data Set</em>'.
	 * @generated
	 */
	BubbleDataSet createBubbleDataSet( );
	/**
	 * Returns a new object of class '<em>Element</em>'.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @return a new object of class '<em>Element</em>'.
	 * @generated
	 */
	DataElement createDataElement( );
	/**
	 * Returns a new object of class '<em>Set</em>'.
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @return a new object of class '<em>Set</em>'.
	 * @generated