* missRate =~ 1.0}. Cache misses include all requests which weren't cache hits, including
   * requests which resulted in either successful or failed loading attempts, and requests which
   * waited for other threads to finish loading. It is thus the case that {@code missCount >=
   * loadSuccessCount + loadExceptionCount}. Multiple concurrent misses for the same key will result
   * in a single load operation.
   */
  public double missRate() {

   * missRate =~ 1.0}. Cache misses include all requests which weren't cache hits, including
   * requests which resulted in either successful or failed loading attempts, and requests which
   * waited for other threads to finish loading. It is thus the case that {@code missCount >=
   * loadSuccessCount + loadExceptionCount}. Multiple concurrent misses for the same key will result
   * in a single load operation.
   */
  public double missRate() {