monitorTarget.append(buf, "key1", () -> "value1");
        buf.append(",");
        monitorTarget.append(buf, "key2", () -> 123);
        buf.append(",");
        monitorTarget.append(buf, "key3", () -> null);

        assertEquals("\"key1\":\"value1\",\"key2\":123,\"key3\":null", buf.toString());
    }

    // Test append with empty string
    @Test

        StringBuilder sb = new StringBuilder();
        sb.append(dm).append(createdTime);
        sb.append(dm).append(expiredTime);
        sb.append(dm).append(name);
        sb.append(dm).append(sessionId);
        if (sb.length() > dm.length()) {
            sb.delete(0, dm.length());
        }
        sb.insert(0, "{").append("}");
        return sb.toString();
    }

        StringBuilder sb = new StringBuilder();
        sb.append(dm).append(crawlingInfoId);
        sb.append(dm).append(createdTime);
        sb.append(dm).append(key);
        sb.append(dm).append(value);
        if (sb.length() > dm.length()) {
            sb.delete(0, dm.length());
        }
        sb.insert(0, "{").append("}");
        return sb.toString();
    }

        sb.append(dm).append(createdBy);
        sb.append(dm).append(createdTime);
        sb.append(dm).append(processType);
        sb.append(dm).append(regex);
        sb.append(dm).append(replacement);
        sb.append(dm).append(sortOrder);
        sb.append(dm).append(updatedBy);
        sb.append(dm).append(updatedTime);
        sb.append(dm).append(userAgent);

	o = msgp.Require(b, z.Msgsize())
	// map header, size 8
	// string "Bucket"
	o = append(o, 0x88, 0xa6, 0x42, 0x75, 0x63, 0x6b, 0x65, 0x74)
	o = msgp.AppendString(o, z.Bucket)
	// string "BaseDir"
	o = append(o, 0xa7, 0x42, 0x61, 0x73, 0x65, 0x44, 0x69, 0x72)
	o = msgp.AppendString(o, z.BaseDir)
	// string "Recursive"
	o = append(o, 0xa9, 0x52, 0x65, 0x63, 0x75, 0x72, 0x73, 0x69, 0x76, 0x65)
	o = msgp.AppendBool(o, z.Recursive)

        path.append(artifact.getGroupId()).append('/');

        path.append(artifact.getExtension()).append("s/");

        path.append(artifact.getArtifactId()).append('-').append(artifact.getVersion());

        if (!artifact.getClassifier().isEmpty()) {
            path.append('-').append(artifact.getClassifier());
        }

        path.append('.').append(artifact.getExtension());

        commandWithRetry.append(indent).append("  ").append(command).append(" && \n");
        commandWithRetry.append(indent).append("  exit_code=0 && break || \n");
        commandWithRetry.append(indent);
        commandWithRetry.append("    exit_code=$? && echo \"").append(name).append(" error: retry $iter in 10s\" && sleep 10; \n");
        commandWithRetry.append(indent).append("done; \n");

	o = append(o, 0xa2, 0x6e, 0x6f)
	o = msgp.AppendUint64(o, z.NumObjects)
	// string "nv"
	o = append(o, 0xa2, 0x6e, 0x76)
	o = msgp.AppendUint64(o, z.NumVersions)
	// string "bs"
	o = append(o, 0xa2, 0x62, 0x73)
	o = msgp.AppendUint64(o, z.Bytes)
	// string "par"
	o = append(o, 0xa3, 0x70, 0x61, 0x72)
	o = msgp.AppendBool(o, z.Participating)
	// string "inf"
	o = append(o, 0xa3, 0x69, 0x6e, 0x66)

	// string "v"
	o = append(o, 0xa1, 0x76)
	o = msgp.AppendString(o, z.Volume)
	// string "ov"
	o = append(o, 0xa2, 0x6f, 0x76)
	o = msgp.AppendString(o, z.OrigVolume)
	// string "fp"
	o = append(o, 0xa2, 0x66, 0x70)
	o = msgp.AppendString(o, z.FilePath)
	// string "uo"
	o = append(o, 0xa2, 0x75, 0x6f)
	// map header, size 1
	// string "np"
	o = append(o, 0x81, 0xa2, 0x6e, 0x70)

        StringBuilder ret = new StringBuilder().append(this.proto).append(":").append(this.server).append("[").append(this.endpoint);
        if (this.options != null) {
            for (final Entry<String, Object> entry : this.options.entrySet()) {
                ret.append(",").append(entry.getKey()).append("=").append(entry.getValue());
            }
        }
        ret.append("]");
        return ret.toString();
    }