Bug 104986 Backgound image uses an absolute path
Currently Chart uses an absolute path to indicate a backgournd image, that may cause the design unusable on other environments. Expected the background image can be definded in multiple ways like in report designer. e.g. URI(absolute path), File(relative path), Embedded Image(Encoded Image Data).
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/model/attribute/util/AttributeSwitch.java
*/
	public Object caseBounds( Bounds object )
	{
		return null;
	}
	/**
	 * Returns the result of interpretting the object as an instance of '<em>Call Back Value</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>Call Back Value</em>'.
	 * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
	 * @generated
	 */
	public Object caseCallBackValue( CallBackValue object )
	{
		return null;
	}
	/**
	 * Returns the result of interpretting the object as an instance of '<em>Color Definition</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>Color Definition</em>'.
	 * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
	 * @generated
	 */
	public Object caseColorDefinition( ColorDefinition object )