extensions/typescript-language-features/src/tsServer/bufferSyncSupport.ts/TabResourceTracker/getResourcesForTab
class TabResourceTracker:	private getResourcesForTab(tab: vscode.Tab): vscode.Uri[] {
		if (tab.input instanceof vscode.TabInputText) {
			return [tab.input.uri];
		} else if (tab.input instanceof vscode.TabInputTextDiff) {
			return [tab.input.original, tab.input.modified];
		} else if (tab.input instanceof vscode.TabInputNotebook) {
			return [tab.input.uri];
		} else {
			return [];
		}
	}