* have to sleep till 3.05 seconds.
     */
    return create(permitsPerSecond, SleepingStopwatch.createFromSystemTimer());
  }

  @VisibleForTesting
  static RateLimiter create(double permitsPerSecond, SleepingStopwatch stopwatch) {
    RateLimiter rateLimiter = new SmoothBursty(stopwatch, 1.0 /* maxBurstSeconds */);
    rateLimiter.setRate(permitsPerSecond);

import com.google.common.collect.Lists;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.NullPointerTester.Visibility;
import com.google.common.util.concurrent.RateLimiter.SleepingStopwatch;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;
import java.util.Locale;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import junit.framework.TestCase;

import com.google.common.collect.Lists;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.NullPointerTester.Visibility;
import com.google.common.util.concurrent.RateLimiter.SleepingStopwatch;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;
import java.util.Locale;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import junit.framework.TestCase;

     * (when permits == maxPermits)
     */
    private double slope;

    private double thresholdPermits;
    private double coldFactor;

    SmoothWarmingUp(
        SleepingStopwatch stopwatch, long warmupPeriod, TimeUnit timeUnit, double coldFactor) {
      super(stopwatch);
      this.warmupPeriodMicros = timeUnit.toMicros(warmupPeriod);
      this.coldFactor = coldFactor;
    }