// corsHandler handler for CORS (Cross Origin Resource Sharing)
func corsHandler(handler http.Handler) http.Handler {
	commonS3Headers := []string{
		xhttp.Date,
		xhttp.ETag,
		xhttp.ServerInfo,
		xhttp.Connection,
		xhttp.AcceptRanges,
		xhttp.ContentRange,
		xhttp.ContentEncoding,
		xhttp.ContentLength,
		xhttp.ContentType,
		xhttp.ContentDisposition,
		xhttp.LastModified,
		xhttp.ContentLanguage,

import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.google.j2objc.annotations.Weak;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;

 * at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Gregory Kick
 * @since 11.0
 */
@GwtCompatible
public abstract class ImmutableTable<R, C, V> extends AbstractTable<R, C, V>
    implements Serializable {

  /**

import static com.google.common.collect.testing.IteratorFeature.SUPPORTS_SET;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;
import static java.util.Collections.emptyList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;

import static com.google.common.collect.Tables.transpose;
import static com.google.common.collect.Tables.unmodifiableRowSortedTable;
import static com.google.common.collect.Tables.unmodifiableTable;
import static java.util.Collections.sort;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Function;

        return items[takeIndex];
      } finally {
        monitor.leave();
      }
    } else {
      return null;
    }
  }

  // this doc comment is overridden to remove the reference to collections
  // greater in size than Integer.MAX_VALUE
  /**
   * Returns the number of elements in this queue.
   *
   * @return the number of elements in this queue
   */
  @CanIgnoreReturnValue
  @Override

import static com.google.common.collect.testing.Helpers.copyToSet;
import static java.lang.System.arraycopy;
import static java.util.Arrays.asList;
import static java.util.Collections.frequency;
import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.fail;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

          .put(CharSource.class, CharSource.empty())
          .put(ByteSink.class, NullByteSink.INSTANCE)
          .put(CharSink.class, NullByteSink.INSTANCE.asCharSink(UTF_8))
          // All collections are immutable empty. So safe for any type parameter.
          .put(Iterator.class, ImmutableSet.of().iterator())
          .put(PeekingIterator.class, Iterators.peekingIterator(ImmutableSet.of().iterator()))

import static com.google.common.collect.testing.Helpers.copyToSet;
import static java.lang.System.arraycopy;
import static java.util.Arrays.asList;
import static java.util.Collections.frequency;
import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.fail;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

 * detailed at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
public class ImmutableListMultimap<K, V> extends ImmutableMultimap<K, V>
    implements ListMultimap<K, V> {
  /**