Bug 207036 [Regression] The chart in an old report design can not be rendered [13]
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/DeferredCacheManager.java
/**
	 * Clear all <code>DeferredCache</code> instances.
	 */
	public void clearDC( )
	{
		fDeferredCacheList.clear( );
		fFirstDC = null;
		fLastDC = null;
		fSingleDC = null;
	}
	/**
	 * Returns first <code>DeferredCache</code> instance.
	 * 
	 * @return first <code>DeferredCache</code> instance.
	 */
	public DeferredCache getFirstDeferredCache( )
	{
		return fFirstDC;
	}
	/**
	 * Returns last <code>DeferredCache</code> instance.
	 * 
	 * @return last <code>DeferredCache</code> instance.
	 */
	public DeferredCache getLastDeferredCache( )
	{
		return fLastDC;
	}
}