Bug 214706 Script UID doens't work for Chart
Use chart "onRender" property handle and call ModuleUtil.getScriptUID(), it generates the id. But later use this id to get back the PropertyHandle or Script content, it fails.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/PropertyHandle.java
return;
		ContentCommand cmd = new ContentCommand( getModule( ),
				new ContainerContext( getElement( ), propDefn.getName( ) ),
				false, false );
		cmd.remove( content.getElement( ) );
	}
	/**
	 * Drops a content element from the slot, and unresolve any reference
	 * property which refers the element to drop.
	 * 
	 * @param content
	 *            a handle to the content to drop
	 * @throws SemanticException
	 *             if the content is not within the slot
	 */
	public void drop( DesignElementHandle content ) throws SemanticException
	{
		if ( content == null )
			return;
		ContentCommand cmd = new ContentCommand( getModule( ),
				new ContainerContext( getElement( ), propDefn.getName( ) ),
				false, true );
		cmd.remove( content.getElement( ) );
	}
	/**
	 * Drops a content element at the given position from the slot, and clear
	 * any reference property which refers the element to drop.
	 * 
	 * @param posn
	 *            the position of the content to drop