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
StockDataSet.class,
				"StockDataSet", !IS_ABSTRACT, !IS_INTERFACE, IS_GENERATED_INSTANCE_CLASS ); 
		initEClass( textDataSetEClass,
				TextDataSet.class,
				"TextDataSet", !IS_ABSTRACT, !IS_INTERFACE, IS_GENERATED_INSTANCE_CLASS ); 
		initEClass( triggerEClass,
				Trigger.class,
				"Trigger", !IS_ABSTRACT, !IS_INTERFACE, IS_GENERATED_INSTANCE_CLASS ); 
		initEAttribute( getTrigger_Condition( ),
				theAttributePackage.getTriggerCondition( ),
				"condition", "Mouse_Hover", 1, 1, Trigger.class, !IS_TRANSIENT, !IS_VOLATILE, IS_CHANGEABLE, IS_UNSETTABLE, !IS_ID, !IS_UNIQUE, !IS_DERIVED, IS_ORDERED ); 
		initEReference( getTrigger_Action( ),
				this.getAction( ),
				null,
				"action", null, 1, 1, Trigger.class, !IS_TRANSIENT, !IS_VOLATILE, IS_CHANGEABLE, IS_COMPOSITE, !IS_RESOLVE_PROXIES, !IS_UNSETTABLE, IS_UNIQUE, !IS_DERIVED, IS_ORDERED ); 
		initEAttribute( getTrigger_TriggerFlow( ),
				theAttributePackage.getTriggerFlow( ),
				"triggerFlow", "Capture", 0, 1, Trigger.class, !IS_TRANSIENT, !IS_VOLATILE, IS_CHANGEABLE, IS_UNSETTABLE, !IS_ID, !IS_UNIQUE, !IS_DERIVED, IS_ORDERED ); 
		
		initEDataType( dataEDataType,
				Object.class,
				"Data", IS_SERIALIZABLE, !IS_GENERATED_INSTANCE_CLASS ); 
		
		createResource( eNS_URI );
		
		
		createExtendedMetaDataAnnotations( );
	}
	/**
	 * Initializes the annotations for