* @since 20.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class StatsAccumulator {

  // These fields must satisfy the requirements of Stats' constructor as well as those of the stat
  // methods of this class.
  private long count = 0;
  private double mean = 0.0; // any finite value will do, we only use it to multiply by zero for sum
  private double sumOfSquaresOfDeltas = 0.0;

 * of the values which would appear at the indexes floor(x) and ceil(x) weighted by (1-frac(x)) and
 * frac(x) respectively. This is the same definition as used by Excel and by S, it is the Type 7
 * definition in <a
 * href="http://stat.ethz.ch/R-manual/R-devel/library/stats/html/quantile.html">R</a>, and it is
 * described by <a
 * href="http://en.wikipedia.org/wiki/Quantile#Estimating_the_quantiles_of_a_population">

@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class PairedStatsAccumulator {

  // These fields must satisfy the requirements of PairedStats' constructor as well as those of the
  // stat methods of this class.
  private final StatsAccumulator xStats = new StatsAccumulator();
  private final StatsAccumulator yStats = new StatsAccumulator();
  private double sumOfProductsOfDeltas = 0.0;

    boolean done = doneSignal.await(1, TimeUnit.SECONDS);
    if (!done) {
      StringBuilder builder = new StringBuilder();
      for (StackTraceElement trace : thread.getStackTrace()) {
        builder.append("\tat ").append(trace).append('\n');
      }
      fail(builder.toString());
    }
  }

    boolean done = doneSignal.await(1, TimeUnit.SECONDS);
    if (!done) {
      StringBuilder builder = new StringBuilder();
      for (StackTraceElement trace : thread.getStackTrace()) {
        builder.append("\tat ").append(trace).append('\n');
      }
      fail(builder.toString());
    }
  }