Scoped custom element registries Demo

This page uses two <contoso-button> custom elements, which are defined in two separate scoped custom element registries.
Without scoped registries, the second definition would throw an error. With scoped registries, both coexist peacefully.

• Two separate scoped registries are created using new CustomElementRegistry().
• Each registry is scoped to a different DOM element via the customElementRegistry option.
• Two <contoso-button> elements are created, one in each DOM element, and using different custom element definitions.
• No naming conflicts. The same tag name has completely different behaviors in different scopes.