Bug 176436 Charts Imported from Libraries do not update when libraries change
During a live presentation of BIRT at EclipseCon, we came across a rather embarassing issue. When charts are included in a library, and imported into a report design from a library, any changes to the library instance of the chart do not reflect in the report itself.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/ExtendedItem.java
}
	/**
	 * Gets the default element definition of this extended-item.
	 * 
	 * @return the default element definition
	 */
	public IElementDefn getDefaultDefn( )
	{
		return super.getDefn( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.parser.treebuild.IContentHandler#getTree()
	 */
	public ContentTree getContentTree( )
	{
		return this.contentTree;
	}
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.report.model.parser.treebuild.IContentHandler#initializeContentTree()
	 */
	
	public void initializeContentTree( )
	{
		if ( contentTree == null )
			contentTree = new ContentTree( );
	}
}