code: public double getUpperBound(final int numStdDev) {
      if (!isEstimationMode()) { return getRetainedEntries(); }
      return BinomialBoundsN.getUpperBound(getRetainedEntries(), getTheta(), numStdDev, isEmpty_);
    }
docs: Gets the approximate upper error bound given the specified number of Standard Deviations.
  This will return getEstimate() if isEmpty() is true.
  
  @param numStdDev
  <a href="{@docRoot}/resources/dictionary.html#numStdDev">See Number of Standard Deviations</a>
  @return the upper bound.