code: public static ExpiryDate fromAbsolute(long expiryDate) {
          long creationTime = System.currentTimeMillis();
          long relativeTtl;
          try {
              relativeTtl = Math.subtractExact(expiryDate, creationTime);
          } catch (ArithmeticException exception) {
              relativeTtl = Long.MIN_VALUE;
          }
          return new ExpiryDate(relativeTtl, expiryDate, creationTime);
      }
docs: NOTE: relative Ttl can be negative if the ExpiryDate passed in was in the past
  @param expiryDate time measured in milliseconds, between the current time and midnight, January 1, 1970 UTC
  @return an ExpiryDate object with creationTime = current time, and relativeTtl = ExpiryDate - creationTime;