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
return errors;
		}
		
		
		
		
		
		if ( !canContainTemplateElement( module, slotId, element ) )
		{
			errors.add( e );
			return errors;
		}
		
		
		if ( isRootIncludedByModule( ) )
		{
			errors.add( e );
			return errors;
		}
		
		
		if ( isVirtualElement( ) || getExtendsName( ) != null )
		{
			errors.add( e );
			return errors;
		}
		
		DesignElement tmpContainer = this;
		while ( tmpContainer != null )
		{