org.linkedin.util-core/src/main/java/org/linkedin/util/clock/Chronos.java
public long tick()
  {
    long tick = _clock.currentTimeMillis();
    long diff = tick - _tick;

    _tick = tick;

    return diff;
  }
public long tick()
  {
    long tick = _clock.currentTimeMillis();
    long diff = tick - _tick;

    _tick = tick;

    return diff;
  }
Returns the number of milliseconds ellapsed since the last call to
this function.

@return the number of milliseconds since last call