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/DataSwitch.java
*/
	public Object caseGanttDataSet( GanttDataSet object )
	{
		return null;
	}
	/**
	 * Returns the result of interpretting the object as an instance of '<em>Number Data Element</em>'. <!--
	 * begin-user-doc --> This implementation returns null; returning a non-null result will terminate the switch. <!--
	 * end-user-doc -->
	 * 
	 * @param object
	 *            the target of the switch.
	 * @return the result of interpretting the object as an instance of '<em>Number Data Element</em>'.
	 * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
	 * @generated
	 */
	public Object caseNumberDataElement( NumberDataElement object )
	{
		return null;
	}
	/**
	 * Returns the result of interpretting the object as an instance of '<em>Number Data Set</em>'. <!--
	 * begin-user-doc --> This implementation returns null; returning a non-null result will terminate the switch. <!--
	 * end-user-doc -->
	 * 
	 * @param object
	 *            the target of the switch.
	 * @return the result of interpretting the object as an instance of '<em>Number Data Set</em>'.
	 * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
	 * @generated