code: public long getTimeDuration(String name, long defaultValue, TimeUnit unit) {
  		String vStr = get(name);
  		if (null == vStr) {
  			return defaultValue;
  		} else {
  			return getTimeDurationHelper(name, vStr, unit);
  		}
  	}
docs: Return time duration in the given time unit. Valid units are encoded in
  properties as suffixes: nanoseconds (ns), microseconds (us), milliseconds
  (ms), seconds (s), minutes (m), hours (h), and days (d).
  @param name Property name
  @param defaultValue Value returned if no mapping exists.
  @param unit Unit to convert the stored property, if it exists.
  @throws NumberFormatException If the property stripped of its unit is not
  a number