return fmt.Errorf("copying %s to %s: %v", src, dst, err)
	}
	return nil
}

// mayberemovefile removes a file only if it is a regular file
// When running as a user with sufficient privileges, we may delete
// even device files, for example, which is not intended.
func mayberemovefile(s string) {
	if fi, err := os.Lstat(s); err == nil && !fi.Mode().IsRegular() {
		return
	}
	os.Remove(s)
}

	}
	reset := func() { s = connRequestSet{} }

	t.Run("add-delete", func(t *testing.T) {
		reset()
		wantLen(0)
		dh := s.Add(nil)
		wantLen(1)
		if !s.Delete(dh) {
			t.Fatal("failed to delete")
		}
		wantLen(0)
		if s.Delete(dh) {
			t.Error("delete worked twice")
		}
		wantLen(0)
	})
	t.Run("take-before-delete", func(t *testing.T) {
		reset()
		ch1 := make(chan connRequest)

				w.inferred[i] = nil
			}
		}
		// If we don't have one of our type parameters, the cycle is due
		// to an ordinary recursive type and we can just stop walking it.
		return
	}
	w.seen[typ] = true
	defer delete(w.seen, typ)

	switch t := typ.(type) {
	case *Basic:
		// nothing to do

	// *Alias:
	//      This case should not occur because of Unalias(typ) at the top.

	case *Array:
		w.typ(t.elem)

				w.inferred[i] = nil
			}
		}
		// If we don't have one of our type parameters, the cycle is due
		// to an ordinary recursive type and we can just stop walking it.
		return
	}
	w.seen[typ] = true
	defer delete(w.seen, typ)

	switch t := typ.(type) {
	case *Basic:
		// nothing to do

	// *Alias:
	//      This case should not occur because of Unalias(typ) at the top.

	case *Array:
		w.typ(t.elem)

	Domain     string    // optional
	Expires    time.Time // optional
	RawExpires string    // for reading cookies only

	// MaxAge=0 means no 'Max-Age' attribute specified.
	// MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'
	// MaxAge>0 means Max-Age attribute present and given in seconds
	MaxAge      int
	Secure      bool
	HttpOnly    bool
	SameSite    SameSite
	Partitioned bool
	Raw         string

	cache.Put(keys[0], nil)
	if _, ok := cache.Get(keys[0]); ok {
		t.Fatalf("session cache failed to delete key 0")
	}

	// Delete entry 2. LRU should keep 4 and 5
	cache.Put(keys[2], nil)
	if _, ok := cache.Get(keys[2]); ok {
		t.Fatalf("session cache failed to delete key 4")
	}
	for i := 4; i < 6; i++ {
		if s, ok := cache.Get(keys[i]); !ok || s != &cs[i] {

			if handleSTW(r) {
				stw--
			} else if handleSweep(r) {
				ps[ev.Proc()].gc--
			} else if handleMarkAssist(r) {
				ps[ev.Proc()].gc--
				if g := r.Scope.Goroutine(); g != NoGoroutine {
					delete(inGC, g)
				}
			}
		case EventStateTransition:
			st := ev.StateTransition()
			if st.Resource.Kind != ResourceGoroutine {
				break
			}
			old, new := st.Goroutine()

	}

	// Extract the module zip directory at its final location.
	//
	// To prevent other processes from reading the directory if we crash,
	// create a .partial file before extracting the directory, and delete
	// the .partial file afterward (all while holding the lock).
	//
	// Before Go 1.16, we extracted to a temporary directory with a random name
	// then renamed it into place with os.Rename. On Windows, this failed with

	}

	noParens := func(r rune) rune {
		if r == '(' || r == ')' {
			return -1
		}
		return r
	}

	for _, marked := range nextStdChunkTests {
		// marked is an expected output from markChunks.
		// If we delete the parens and pass it through markChunks,
		// we should get the original back.
		format := strings.Map(noParens, marked)
		out := markChunks(format)
		if out != marked {

		canDashC = false
	case "1":
		canDashC = true
	case "":
		// Not set. Use default.
	default:
		log.Fatalf("GO19CONCURRENTCOMPILATION must be 0, 1, or unset, got %q", e)
	}

	// TODO: Test and delete these conditions.
	if cfg.ExperimentErr != nil || cfg.Experiment.FieldTrack || cfg.Experiment.PreemptibleLoops {
		canDashC = false
	}

	if !canDashC {
		return 1
	}