* @param workingDirectory working directory
     * @param stdout stdout
     * @param stderr stderr
     * @return return code
     */
    public int doMain(String[] args, String workingDirectory, PrintStream stdout, PrintStream stderr) {
        PrintStream oldout = System.out;
        PrintStream olderr = System.err;

        final Set<String> realms;
        if (classWorld != null) {

		case *rsa.PrivateKey:
			return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}
		case *ecdsa.PrivateKey:
			b, err := x509.MarshalECPrivateKey(k)
			if err != nil {
				fmt.Fprintf(os.Stderr, "Unable to marshal ECDSA private key: %v", err)
				os.Exit(2)
			}
			return &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}
		default:
			return nil
		}
	}

	var priv any
	var err error

	readQuorum, writeQuorum, err := objectQuorumFromMeta(ctx, metaArr, errs, er.defaultParityCount)
	if err != nil {
		if shouldCheckForDangling(err, errs, srcBucket) {
			_, derr := er.deleteIfDangling(context.Background(), srcBucket, srcObject, metaArr, errs, nil, srcOpts)
			if derr == nil {
				if srcOpts.VersionID != "" {
					err = errFileVersionNotFound
				} else {
					err = errFileNotFound
				}
			}
		}

		}
	}()
	b.Read(make([]byte, 100))
}

var errFake = errors.New("fake error")

type errorThenGoodReader struct {
	didErr bool
	nread  int
}

func (r *errorThenGoodReader) Read(p []byte) (int, error) {
	r.nread++
	if !r.didErr {
		r.didErr = true
		return 0, errFake
	}
	return len(p), nil
}

func TestReaderClearError(t *testing.T) {
	r := &errorThenGoodReader{}