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 the name behind the last separator "."
	 */
	public static String getElementName( Object obj )
	{
		if ( obj instanceof Class )
		{
			obj = ( (Class) obj ).getName( );
		}
		return obj.toString( )
				.substring( obj.toString( ).lastIndexOf( "." ) + 1 ); 
	}
	/**
	 * Gets the definition for the element with the specified name
	 * 
	 * @param elementName
	 *            the name of the element
	 * 
	 * @return Returns the definition, or null if the element is not defined.
	 */
	public static IElementDefn getElementDefn( String elementName )
	{
		IElementDefn defn = getMetaDataDictionary( ).getElement( elementName );
		if ( defn == null )
		{
			defn = getMetaDataDictionary( ).getExtension( elementName );
		}
		return defn;
	}
	/**
	 * Get display label of report element