### Question:
ZipkinManager { public static long hexUnsignedStringToLong(@Nonnull String hexValue) { return new BigInteger(hexValue, HEX_RADIX).longValue(); }  boolean shouldTrace(); @ManagedAttribute int getSamplingLevel(); @ManagedAttribute void setSamplingLevel(int samplingLevel); ZipkinRequestUUID createNewZipkinRequestUUID(@Nonnull RequestUUID cougarUuid, @Nullable String traceId,
                                                        @Nullable String spanId, @Nullable String parentSpanId,
                                                        @Nullable String sampled, @Nullable String flags, int port); static long getRandomLong(); static long hexUnsignedStringToLong(@Nonnull String hexValue);  }### Answer:
@Test public void hexUnsignedStringToLong_Test1() { long result = ZipkinManager.hexUnsignedStringToLong("f"); assertEquals(15, result); }
@Test public void hexUnsignedStringToLong_Test2() { long result = ZipkinManager.hexUnsignedStringToLong("147"); assertEquals(327, result); }
@Test public void hexUnsignedStringToLong_Test3() { long result = ZipkinManager.hexUnsignedStringToLong("7fffffffffffffff"); assertEquals(Long.MAX_VALUE, result); }