assertEquals(Long.valueOf(1), stats.get(EventType.CONFIGURATION_CHANGE), "Should have 1 configuration event");
    }

    @Test
    @DisplayName("Test statistics accumulation")
    void testStatisticsAccumulation() {
        logger.logAuthentication(true, "user1", "DOMAIN", "192.168.1.1");
        logger.logAuthentication(false, "user2", "DOMAIN", "192.168.1.2");

 *   <li>keys automatically wrapped in {@code WeakReference}
 *   <li>values automatically wrapped in {@code WeakReference} or {@code SoftReference}
 *   <li>notification of evicted (or otherwise removed) entries
 *   <li>accumulation of cache access statistics
 * </ul>
 *
 * <p>These features are all optional; caches can be created using all or none of them. By default,

    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(values);
    return accumulator.snapshot();
  }

  /**
   * Returns statistics over a dataset containing the given values.
   *
   * @param values a series of values
   */
  public static Stats of(double... values) {
    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(values);

<img src="/img/tutorial/path-operation-configuration/image01.png">

### Tags with Enums { #tags-with-enums }

If you have a big application, you might end up accumulating **several tags**, and you would want to make sure you always use the **same tag** for related *path operations*.

In these cases, it could make sense to store the tags in an `Enum`.

        // Execute second time - params should be fresh
        Object result2 = scriptExecutor.execute("modifyEngine", "script2");
        assertEquals(2, result2); // Should still be 2, not accumulating
    }

    public void test_shutdown_withListener() {
        // Add shutdown listener
        TestShutdownListener listener = new TestShutdownListener();
        scriptExecutor.addShutdownListener(listener);

        });
    return holder.get();
  }

  /**
   * Updates the value currently associated with {@code key} by combining it with {@code x} via the
   * specified accumulator function, returning the new value. The previous value associated with
   * {@code key} (or zero, if there is none) is passed as the first argument to {@code
   * accumulatorFunction}, and {@code x} is passed as the second argument.

      if (set == null) {
        return ImmutableSet.of();
      }
      ImmutableSet<E> ret = ImmutableEnumSet.asImmutable(set);
      set = null; // subsequent manual manipulation of the accumulator mustn't affect ret
      return ret;
    }
  }

  @GwtIncompatible
  @SuppressWarnings({"rawtypes", "unchecked"})
  static <E extends Comparable<? super E>>

      if (set == null) {
        return ImmutableSet.of();
      }
      ImmutableSet<E> ret = ImmutableEnumSet.asImmutable(set);
      set = null; // subsequent manual manipulation of the accumulator mustn't affect ret
      return ret;
    }
  }

  @GwtIncompatible
  @SuppressWarnings({"rawtypes", "unchecked"})
  static <E extends Comparable<? super E>>

#
#       The "traditional" practice of packing multiple parameters into a
#       space-separated string is a well documented source of bugs and security
#       problems, so this is (mostly) avoided, by progressively accumulating
#       options in "$@", and eventually passing that to Java.
#
#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;

import java.util.Arrays;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Stream;
import org.jspecify.annotations.Nullable;

/**
 * An accumulator that selects the "top" {@code k} elements added to it, relative to a provided
 * comparator. "Top" can mean the greatest or the lowest elements, specified in the factory used to
 * create the {@code TopKSelector} instance.
 *