logger.info("Deleted completed document data: time={}ms", systemHelper.getCurrentTimeAsLong() - execTime);
        }
    }

    /**
     * Forces all crawlers to stop immediately.
     * Sets the force stop flag and stops all active crawler instances.
     */
    private void forceStop() {
        systemHelper.setForceStop(true);
        if (crawlerList != null) {

Not all client code is compiled with NullAway.
Do not make a parameter `@Nullable` just to check and throw a `NullPointerException` when it is `null`. 

## Consequences

* Classes are forced to have consistent nullability annotations.
* IDE warnings become more accurate, reducing warnings fatigue.
* Public API nullability annotations become closer to reality.

 * for exclusive consumption by the repository system and is opaque to the cache implementation.
 *
 */
@Deprecated
//
// Used by Tycho and will break users and force them to upgrade to Maven 3.1 so we should really leave
// this here, possibly indefinitely.
//
public interface RepositoryCache {

    /**

     */
    boolean required() default false;

    /**
     * Specifies that this parameter cannot be configured directly by the user (as in the case of POM-specified
     * configuration). This is useful when you want to force the user to use common POM elements rather than plugin
     * configurations, as in the case where you want to use the artifact's final name as a parameter. In this case, you

 * doesn't cache partial responses.
 *
 * ## Force a Network Response
 *
 * In some situations, such as after a user clicks a 'refresh' button, it may be necessary to skip
 * the cache, and fetch data directly from the server. To force a full refresh, add the `no-cache`
 * directive:
 *
 * ```java
 * Request request = new Request.Builder()

net.core.busy_read=50
net.core.busy_poll=50
kernel.numa_balancing=1

# Do not use swap at all
vm.swappiness=0
vm.vfs_cache_pressure=50

# Start writeback at 3% memory
vm.dirty_background_ratio=3
# Force writeback at 10% memory
vm.dirty_ratio=10

# Quite a few memory map
# areas may be consumed
vm.max_map_count=524288

# Default is 500000 = 0.5ms
kernel.sched_migration_cost_ns=5000000

     * changes: https://mail.openjdk.org/pipermail/core-libs-dev/2013-May/thread.html#17367
     *
     * TODO(cpovirk): decide what the best long-term action here is: force users
     * to suppress (as we do now), stop testing entrySet().add() at all, make
     * entrySet().add() tests tolerant of either behavior, introduce a map
     * feature for entrySet() that supports add(), or something else

        @Test
        @DisplayName("list propagates SmbUnsupportedOperationException from doEnum")
        void list_propagatesUnsupportedOperationException() throws Exception {
            // Arrange: same setup as above to force doEnum -> SmbUnsupportedOperationException
            SmbFile parent = mock(SmbFile.class, RETURNS_DEEP_STUBS);
            SmbResourceLocator locator = mock(SmbResourceLocator.class);

import java.lang.annotation.RetentionPolicy;
import java.lang.reflect.Method;
import java.util.Locale;
import junit.framework.TestCase;

/**
 * Since annotations have some reusability issues that force copy and paste all over the place, it's
 * worth having a test to ensure that all our Feature enums have their annotations correctly set up.
 *
 * @author George van den Driessche
 */

 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Austin Appleby
 */
@GwtCompatible
final class Hashing {
  private Hashing() {}

  /*
   * These should be ints, but we need to use longs to force GWT to do the multiplications with
   * enough precision.
   */
  private static final long C1 = 0xcc9e2d51;
  private static final long C2 = 0x1b873593;

  /*