public static String tagWithPrefix(String prefix, String tag) {
        int length = tag.length();
        StringBuilder withPrefix = new StringBuilder(MAX_TAG_LENGTH);
        withPrefix.append(prefix);
        withPrefix.append("[");
        if (length >= MAX_TAG_LENGTH - prefix.length()) {
            // truncate
            withPrefix.append(tag.substring(0, MAX_TAG_LENGTH - prefix.length()));
        } else {
            withPrefix.append(tag);
        }
        withPrefix.append("]");
        return withPrefix.toString();
    }
@param tag The {@link String} tag to use when logging
@return The prefixed {@link String} tag to use when logging
android/android_framework/base/src/main/java/com/elvishew/xlog/XLog.java