- The extension implements and registers a [`TextDocumentContentProvider`](http://code.visualstudio.com/docs/extensionAPI/vscode-api#TextDocumentContentProvider) for a particular URI scheme.
- The content provider uses the [`vscode.executeReferenceProvider`](http://code.visualstudio.com/docs/extensionAPI/vscode-api-commands)-API command to delegate searching for references to the language extensions, like TypeScript, vscode-go, or C#
- The generated document initially contains a caption only and incrementally updates as each reference location is resolved.