whole_func_string: async function tryShutdown () {
      if (jobsToComplete === 0) {
        await new Promise((resolve) => { setTimeout(resolve, 500) })
        await worker.end()
        process.exit()
      }
    }
func_code_string: async function tryShutdown () {
      if (jobsToComplete === 0) {
        await new Promise((resolve) => { setTimeout(resolve, 500) })
        await worker.end()
        process.exit()
      }
    }
func_documentation_string: just a helper for this demo