ImmutableBiMap<K, V> bimap = (ImmutableBiMap<K, V>) map;
      // TODO(lowasser): if we need to make a copy of a BiMap because the
      // forward map is a view, don't make a copy of the non-view delegate map
      if (!bimap.isPartialView()) {
        return bimap;
      }
    }
    return copyOf(map.entrySet());
  }

  /**

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.BiMap;
import com.google.common.collect.testing.SampleElements;
import java.util.List;
import java.util.Map.Entry;

/**
 * Implementation helper for {@link TestBiMapGenerator} for use with bimaps of strings.
 *
 * @author Chris Povirk
 * @author Jared Levy
 * @author George van den Driessche

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.BiMap;
import com.google.common.collect.testing.SampleElements;
import java.util.List;
import java.util.Map.Entry;

/**
 * Implementation helper for {@link TestBiMapGenerator} for use with bimaps of strings.
 *
 * @author Chris Povirk
 * @author Jared Levy
 * @author George van den Driessche

    assertEquals(bimap1, bimap2);
    bimap2.inverse().put(Country.SWITZERLAND, Currency.FRANC);
    assertEquals(Country.SWITZERLAND, bimap2.get(Currency.FRANC));
    assertNull(bimap1.get(Currency.FRANC));
    assertFalse(bimap2.equals(bimap1));

    /* Test that it can be empty. */
    EnumBiMap<Currency, Country> emptyBimap = EnumBiMap.create(Currency.class, Country.class);

  }

  // BiMap-specific tests

  @SuppressWarnings("DoNotCall")
  public void testForcePut() {
    BiMap<String, Integer> bimap = ImmutableBiMap.copyOf(ImmutableMap.of("one", 1, "two", 2));
    assertThrows(UnsupportedOperationException.class, () -> bimap.forcePut("three", 3));
  }

  public void testKeySet() {
    ImmutableBiMap<String, Integer> bimap =

            .collect(toImmutableList()),
        n -> n * log(n),
        ImmutableList.of(
            QueryOp.create("BiMap.get", BiMap::get, Math::log),
            QueryOp.create("BiMap.inverse.get", (bm, o) -> bm.inverse().get(o), Math::log)));
  }

  /** All the ways to create an ImmutableBiMap. */
  enum ConstructionPathway {
    COPY_OF_MAP {
      @Override

      public <K extends Comparable<K>, V> BiMap<K, V> create(Map<K, V> map) {
        return HashBiMap.create(map);
      }
    },
    ImmutableBiMapImpl {
      @Override
      public <K extends Comparable<K>, V> BiMap<K, V> create(Map<K, V> map) {
        return ImmutableBiMap.copyOf(map);
      }
    };

    @Override
    public abstract <K extends Comparable<K>, V> BiMap<K, V> create(Map<K, V> map);
  }

      implements TestMapGenerator<K, V>, DerivedGenerator {

    private final OneSizeTestContainerGenerator<BiMap<K, V>, Entry<K, V>> generator;

    public MapGenerator(
        OneSizeTestContainerGenerator<BiMap<K, V>, Entry<K, V>> oneSizeTestContainerGenerator) {
      this.generator = oneSizeTestContainerGenerator;
    }

    @Override

import com.google.common.collect.BiMap;
import com.google.common.collect.testing.AbstractMapTester;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map.Entry;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/** Skeleton for a tester of a {@code BiMap}. */
@GwtCompatible

      public <K extends Comparable<K>, V> BiMap<K, V> create(Map<K, V> map) {
        return HashBiMap.create(map);
      }
    },
    ImmutableBiMapImpl {
      @Override
      public <K extends Comparable<K>, V> BiMap<K, V> create(Map<K, V> map) {
        return ImmutableBiMap.copyOf(map);
      }
    };

    @Override
    public abstract <K extends Comparable<K>, V> BiMap<K, V> create(Map<K, V> map);
  }