public static String bundleToString(Bundle bundle) {
        if (bundle == null) {
            return "null";
        }

        StringBuilder b = new StringBuilder(128);
        b.append("Bundle[{");
        bundleToShortString(bundle, b);
        b.append("}]");
        return b.toString();
    }
Bundle object to string, the string would be in the format of "Bundle[{...}]".
android/android_framework/base/src/main/java/com/elvishew/xlog/internal/util/ObjectToStringUtil.java