extensions/typescript-language-features/src/tsServer/bufferSyncSupport.ts/TabResourceTracker/delete
class TabResourceTracker:	private delete(tab: vscode.Tab): vscode.Uri[] {
		const closedResources: vscode.Uri[] = [];
		for (const uri of this.getResourcesForTab(tab)) {
			const entry = this._tabResources.get(uri);
			if (!entry) {
				continue;
			}

			entry.tabs.delete(tab);
			if (entry.tabs.size === 0) {
				this._tabResources.delete(uri);
				closedResources.push(uri);
			}
		}
		return closedResources;
	}