public static String toLowerHex(long v) {
    char[] data = RecyclableBuffers.parseBuffer();
    writeHexLong(data, 0, v);
    return new String(data, 0, 16);
  }
@Test void toLowerHex_midValue() {
    assertThat(toLowerHex(3405691582L)).isEqualTo("00000000cafebabe");
  }