src/vs/workbench/api/browser/mainThreadCustomEditors.ts/MainThreadCustomEditors/getCustomEditorModel
class MainThreadCustomEditors:	private async getCustomEditorModel(resourceComponents: UriComponents, viewType: string) {
		const resource = URI.revive(resourceComponents);
		const model = await this._customEditorService.models.get(resource, viewType);
		if (!model || !(model instanceof MainThreadCustomEditorModel)) {
			throw new Error('Could not find model for webview editor');
		}
		return model;
	}