code: private String format(final Instant instant) {
  		synchronized (formatter) {
  			if (!instant.equals(lastInstant)) {
  				lastInstant = instant;
  				lastFormat = formatter.format(instant);
  			}
  			return lastFormat;
  		}
  	}
docs: Formats an {@link Instant}.
  
  @param instant
  Instant to format
  @return Formatted instant