Method add

src/typings/vscode.d.ts:17994–17994

* Adds the test item to the children. If an item with the same ID already * exists, it'll be replaced. * @param item Item to add.

(item: TestItem)

		 * @param item Item to add.
		 */
		add(item: TestItem): void;

		/**
		 * Removes a single test item from the collection.