code: async function erase(ws) {
      await unlink(ws.path)
      if (ws.writable) {
          await endStream(ws)
      }
      return ws
  }
docs: Unlink a file based on its WriteStream and close the underlying stream.
  @param {Writable} ws Writable of a file
  @returns {Promise.<Writable>} Closed writable stream