Bug 213680 [2.2.2]Chart script can not be cleaned completely.
Description: Reset script or delete all script does not work. build version: v20071221-0630 steps to reproduce: 1. New a report. 2. New a chart. 3. Enter some script for the chart and save the report. 4. Click the reset scirpt button or delete all script. 5. Save the report and switch to layout,then switch back to script page. Expected result: Script are cleaned. Actual result: Script are not cleaned. Note: If you delete part of the script, it works.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/ExtendedItem.java
*/
	public IReportItem getExtendedElement( )
	{
		return provider.getExtensionElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#baseClone()
	 */
	protected Object baseClone( ) throws CloneNotSupportedException
	{
		ExtendedItem clonedElement = (ExtendedItem) super.baseClone( );
		clonedElement.provider = PeerExtensibilityProviderFactory
				.createProvider( clonedElement, clonedElement.extensionName );
		clonedElement.provider.copyFrom( provider );
		return clonedElement;
	}
	/**
	 * Tests whether the property is a dynamic property of extended element or
	 * not.
	 * 
	 * @param propName
	 *            the property name to check
	 * @return true if the property is one of the dynamic properties for
	 *         extended element, otherwise false
	 */
	public boolean isExtensionModelProperty( String propName )
	{
		return provider.isExtensionModelProperty( propName );