return key, ErrInvalidCustomerKey
	}
	keyMD5, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCustomerKeyMD5))
	if md5Sum := md5.Sum(clientKey); err != nil || !bytes.Equal(md5Sum[:], keyMD5) {
		return key, ErrCustomerKeyMD5Mismatch
	}
	copy(key[:], clientKey)
	return key, nil
}

// UnsealObjectKey extracts and decrypts the sealed object key

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Derived suite generators for Guava collection interfaces, split out of the suite builders so that
 * they are available to GWT.
 *
 * @author Louis Wasserman
 */
@GwtCompatible

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multiset;
import com.google.common.collect.testing.TestCollectionGenerator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates multisets, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 * limitations under the License.
 */

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates maps, containing sample elements, to be tested.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An interface for all filtered multimap types.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multiset;
import com.google.common.collect.testing.TestCollectionGenerator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates multisets, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.util.SortedMap;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An object representing the differences between two sorted maps.
 *
 * @author Louis Wasserman
 * @since 8.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtIncompatible;
import java.util.SortedSet;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Superinterface of {@link SortedMultiset} to introduce a bridge method for {@code elementSet()},
 * to ensure binary compatibility with older Guava versions that specified {@code elementSet()} to

 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Function;
import java.util.ListIterator;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An iterator that transforms a backing list iterator; for internal use. This avoids the object
 * overhead of constructing a {@link Function} for internal methods.
 *
 * @author Louis Wasserman
 */

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Basic implementation of a {@link SortedSetMultimap} with a sorted key set.
 *
 * <p>This superclass allows {@code TreeMultimap} to override methods to return navigable set and