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
return ganttDataSetEClass;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public EClass getNumberDataElement( )
	{
		return numberDataElementEClass;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public EAttribute getNumberDataElement_Value( )
	{
		return (EAttribute) numberDataElementEClass.getEStructuralFeatures( )
				.get( 0 );
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated
	 */
	public EClass getNumberDataSet( )
	{
		return numberDataSetEClass;
	}
	/**
	 * <!-- begin-user-doc --> <!-- end-user-doc -->
	 * @generated