Bug 138562 Splite extendsexcpetion to seperate sub class
The suggestion is Parent invalid Cycle extends Different type extends Not top level extends
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
if ( container instanceof TemplateParameterDefinition )
		{
			assert containerSlotID == TemplateParameterDefinition.DEFAULT_SLOT;
			return false;
		}
		
		
		
		DesignElement element = this;
		if ( element instanceof TemplateParameterDefinition )
		{
			List clients = ( (TemplateParameterDefinition) element )
					.getClientList( );
			if ( clients.size( ) != 0 )
				return false;
		}
		return true;
	}
	/**
	 * Determines if the slot can contain a given element.
	 * 
	 * @param module
	 *            the module
	 * @param slotId
	 *            the slot id
	 * @param element
	 *            the element to insert
	 * @return a list containing exceptions.