return StringUtil.isBlank(s) ? StringUtil.EMPTY : "/" + s;
    }

    public String getVirtualHostKey() {
        return LaRequestUtil.getOptionalRequest().map(req -> (String) req.getAttribute(FessConfig.VIRTUAL_HOST_VALUE)).orElseGet(() -> {
            final String value = processVirtualHost(s -> s, StringUtil.EMPTY);

import java.util.Collection;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import junit.framework.TestCase;

/**
 * {@link LoadingCache} tests that deal with empty caches.
 *
 * @author mike nonemacher
 */

public class EmptyCachesTest extends TestCase {

  public void testEmpty() {
    for (LoadingCache<Object, Object> cache : caches()) {
      checkEmpty(cache);

    // occur in practice.
    if (safeMin >= Character.MIN_HIGH_SURROGATE) {
      // The safe range is empty or the all safe code points lie in or above the
      // surrogate range. Either way the character range is empty.
      this.safeMinChar = Character.MAX_VALUE;
      this.safeMaxChar = 0;
    } else {
      // The safe range is non-empty and contains values below the surrogate

import java.util.Collection;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import junit.framework.TestCase;

/**
 * {@link LoadingCache} tests that deal with empty caches.
 *
 * @author mike nonemacher
 */

public class EmptyCachesTest extends TestCase {

  public void testEmpty() {
    for (LoadingCache<Object, Object> cache : caches()) {
      checkEmpty(cache);

        if (config == null) {
            return OptionalThing.empty();
        }
        final String pipeline = config.getConfigParameterMap(ConfigName.CONFIG).get(Config.PIPELINE);
        if (StringUtil.isBlank(pipeline)) {
            return OptionalThing.empty();
        }
        return OptionalThing.of(pipeline);
    }

    public void refresh() {

  const TF_Output* inputs_ptr = inputs_.empty() ? nullptr : &inputs_[0];
  TF_Tensor* const* input_values_ptr =
      input_values_.empty() ? nullptr : &input_values_[0];

  const TF_Output* outputs_ptr = outputs_.empty() ? nullptr : &outputs_[0];
  TF_Tensor** output_values_ptr =
      output_values_.empty() ? nullptr : &output_values_[0];

  TF_Operation* const* targets_ptr = targets_.empty() ? nullptr : &targets_[0];

        if (synonymLoader.getSynonymMap() == null) {
            if (settings.getAsList("synonyms", null) != null) {
                logger.warn("synonyms values are empty.");
            } else if (settings.get("synonyms_path") != null) {
                logger.warn("synonyms_path[{}] is empty.", settings.get("synonyms_path"));
            } else {
                logger.debug("No synonym data.");
            }
        }
    }

    @Override

@GwtCompatible
@Immutable
@ElementTypesAreNonnullByDefault
public final class ImmutableIntArray implements Serializable {
  private static final ImmutableIntArray EMPTY = new ImmutableIntArray(new int[0]);

  /** Returns the empty array. */
  public static ImmutableIntArray of() {
    return EMPTY;
  }

  /** Returns an immutable array containing a single value. */
  public static ImmutableIntArray of(int e0) {

    assertTrue(collection.contains(e0()));
  }

  /*
   * AbstractCollection fails the removeAll(null) test when the subject
   * collection is empty, but we'd still like to test removeAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)

  /**
   * The freshness level at which the {@link Empty @Empty} annotated method was invoked to generate
   * instance.
   */
  private final Map<Type, Integer> emptyInstanceGenerated = new HashMap<>();

  final <T> void addSampleInstances(Class<T> type, Iterable<? extends T> instances) {
    sampleInstances.putAll(checkNotNull(type), checkNotNull(instances));
  }