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/DataPackage.java
* <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @return the meta object for the attribute '<em>Trigger Flow</em>'.
	 * @see org.eclipse.birt.chart.model.data.Trigger#getTriggerFlow()
	 * @see #getTrigger()
	 * @generated
	 */
	EAttribute getTrigger_TriggerFlow( );
	/**
	 * Returns the meta object for data type '{@link java.lang.Object <em>Data</em>}'.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @return the meta object for data type '<em>Data</em>'.
	 * @see java.lang.Object
	 * @model instanceClass="java.lang.Object"
	 *        extendedMetaData="name='Data'" 
	 * @generated
	 */
	EDataType getData( );
	/**
	 * Returns the factory that creates the instances of the model. <!--
	 * begin-user-doc --> <!-- end-user-doc -->
	 * 
	 * @return the factory that creates the instances of the model.
	 * @generated
	 */
	DataFactory getDataFactory( );
	/**
	 * <!-- begin-user-doc -->
	 * Defines literals for the meta objects that represent