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
.hasNext( ) )
				{
					return (ReportItemHandle) handle;
				}
			}
			ReportItemHandle result = getBindingHolder( handle.getContainer( ) );
			if ( result == null
					&& handle instanceof ReportItemHandle
					&& !( handle instanceof GridHandle ) )
			{
				result = (ReportItemHandle) handle;
			}
			return result;
		}
		return null;
	}
	/**
	 * Return the first DataSetHandle for a report item.
	 * 
	 * If the report item has no DataSetHandle, search for it's container if
	 * container is not a ListingHandle.
	 * 
	 * @param handle
	 *            the ReportItemHandle
	 * @return Available DataSetHandle
	 */
	public static DataSetHandle getFirstDataSet( DesignElementHandle handle )
	{
		DataSetHandle dataSetHandle = null;
		if ( handle instanceof ReportItemHandle )