public static char[] shortStringBuffer() {
    char[] shortStringBuffer = SHORT_STRING_BUFFER.get();
    if (shortStringBuffer == null) {
      shortStringBuffer = new char[SHORT_STRING_LENGTH];
      SHORT_STRING_BUFFER.set(shortStringBuffer);
    }
    return shortStringBuffer;
  }
Returns a {@link ThreadLocal} reused {@code char[]} for use when decoding bytes into hex, IP
literals, or {@link #SHORT_STRING_LENGTH short strings}. The buffer must never be leaked
outside the method. Most will {@link String#String(char[], int, int) copy it into a string}.
zipkin/src/main/java/zipkin2/internal/RecyclableBuffers.java