Bug 389229 Documentation of possible values/objects of property IDeviceRenderer.FILE_IDENTIFIER
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/device/IDeviceRenderer.java
*/
	public static final String COMPRESSED_OUTPUT = "output.compressed"; 
	/**
	 * A property name that indicates the dpi (dots/pixels per inch) resolution
	 * to use when rendering to the device. This is used to convert 'points' in
	 * pixels (a point is 1/72 inch). If not indicated, it will use the default
	 * dpi resolution of the corresponding display server (typically 96dpi)
	 */
	public static final String DPI_RESOLUTION = "device.resolution"; 
	/**
	 * A Property to enable/disable the caching of the image stream on disk
	 * Default is false.
	 */
	public static final String CACHE_ON_DISK = "device.disk.cache"; 
	
	/**
	 * A property name that indicates if alt attribute in area tag of image map
	 * will be used to display data point value.
	 */
	public static final String AREA_ALT_ENABLED = "enable.area.alt"; 
	/**
	 * Device-specific write-only properties that may be set for each device
	 * renderer
	 * 
	 * @param sProperty
	 *            The property whose value is to be set
	 * @param oValue
	 *            The value associated with the property
	 */
	void setProperty( String sProperty, Object oValue );