code: func GetT(t testing.T, n int) (ports []int) {
  	ports, err := Free(n)
  	if err != nil {
  		t.Fatalf("Failed retrieving free port: %v", err)
  	}
  
  	return ports
  }
docs: // GetT is suitable for use when retrieving unused ports in tests. If there is
  // an error retrieving free ports, the test will be failed.