Bug 167545 Copy a cascading parameter group and paste it to another parameter group causes an exception thrown
Steps to reproduce: 1.Copy a cascading parameter group using short cut key "Ctrl+x"/"Ctrl+c", or choosing context menu "Cut"/"Copy"; 2.Paste it to another parameter group using short cut key "Ctrl+v", or choosing context menu "Paste"; Expected result: The source one is pasted in the destination. Actual result: An exception thrown org.eclipse.birt.report.model.api.command.ContentException: The Cascading Parameter Group("Source") is not allowed in the slot (parameters) of Parameter Group("Destination").
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
return exp;
	}
	/**
	 * Returns the level between the holder and the given handle
	 * 
	 * @param holder
	 *            the handle of the holder
	 * @param baseElement
	 *            the handle of the base element
	 * 
	 * @return the level between the holder and the base element, or -1 if the
	 *         element is not a children of the holder
	 */
	public static int getBindingLevel( DesignElementHandle holder,
			DesignElementHandle baseElement )
	{
		int level = 0;
		for ( DesignElementHandle elementHandle = baseElement; elementHandle.getContainer( ) != null; elementHandle = getBindingHolder( elementHandle ).getContainer( ), level++ )
		{
			DesignElementHandle bindingHolder = getBindingHolder( elementHandle );
			if ( bindingHolder == holder )
			{
				return level;
			}
			if ( holder instanceof GroupHandle
					&& bindingHolder == holder.getContainer( ) )
			{
				return level;
			}
		}