@Override
    public Object call() {
      return Boolean.TRUE;
    }
  }

  public static final String TEST_STRING = "a test string";

  public static class StringTask implements Callable<String> {
    @Override
    public String call() {
      return TEST_STRING;
    }
  }

  public Callable<String> latchAwaitingStringTask(final CountDownLatch latch) {

		if err != nil {
			t.Fatalf("large get: %v", err)
		}
		buf := make([]byte, len(testString))
		n, err := io.ReadFull(res.Body, buf)
		if err != nil {
			t.Fatalf("partial read of large response: size=%d, %v", n, err)
		}
		if e, g := testString, string(buf); e != g {
			t.Errorf("partial read got %q, expected %q", g, e)
		}
		res.Body.Close()

	cmd.Env = append(cmd.Environ(), "FOO=foo\x00BAR=bar")
	out, err := cmd.CombinedOutput()
	if err == nil {
		t.Errorf("output = %q; want error", string(out))
	}
}

func TestString(t *testing.T) {
	t.Parallel()

	echoPath, err := exec.LookPath("echo")
	if err != nil {
		t.Skip(err)
	}
	tests := [...]struct {
		path string
		args []string
		want string
	}{