public static String uNibble(int v) {
    char[] result = new char[1];

    result[0] = Character.forDigit(v & 0x0f, 16);
    return new String(result);
  }
Formats an {@code int} as a 4-bit unsigned hex nibble.

@param v value to format
@return {@code non-null;} formatted form
android/android_framework/dex-maker/src/main/java/com/android/dx/util/Hex.java