import static com.google.common.collect.Multisets.intersection;
import static com.google.common.collect.Multisets.sum;
import static com.google.common.collect.Multisets.union;
import static com.google.common.collect.Multisets.unmodifiableMultiset;
import static java.util.Arrays.asList;
import static java.util.Collections.sort;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Objects;

import static com.google.common.collect.Multisets.intersection;
import static com.google.common.collect.Multisets.sum;
import static com.google.common.collect.Multisets.union;
import static com.google.common.collect.Multisets.unmodifiableMultiset;
import static java.util.Arrays.asList;
import static java.util.Collections.sort;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Objects;

 */

package com.google.common.collect;

import static com.google.common.collect.Sets.unmodifiableNavigableSet;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multisets.UnmodifiableMultiset;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.util.Comparator;
import java.util.NavigableSet;
import javax.annotation.CheckForNull;

      Multiset<? extends E> multiset) {
    if (multiset instanceof UnmodifiableMultiset || multiset instanceof ImmutableMultiset) {
      @SuppressWarnings("unchecked") // Since it's unmodifiable, the covariant cast is safe
      Multiset<E> result = (Multiset<E>) multiset;
      return result;
    }
    return new UnmodifiableMultiset<>(checkNotNull(multiset));
  }

      Multiset<? extends E> multiset) {
    if (multiset instanceof UnmodifiableMultiset || multiset instanceof ImmutableMultiset) {
      @SuppressWarnings("unchecked") // Since it's unmodifiable, the covariant cast is safe
      Multiset<E> result = (Multiset<E>) multiset;
      return result;
    }
    return new UnmodifiableMultiset<>(checkNotNull(multiset));
  }

    }

    @Override
    public Multiset<K> keys() {
      Multiset<K> result = keys;
      if (result == null) {
        keys = result = Multisets.unmodifiableMultiset(delegate.keys());
      }
      return result;
    }

    @Override
    public Set<K> keySet() {
      Set<K> result = keySet;
      if (result == null) {