public void testEmptyBuilder() {
    ImmutableMap<String, Integer> map = new Builder<String, Integer>().buildOrThrow();
    assertEquals(Collections.<String, Integer>emptyMap(), map);
  }

  public void testSingletonBuilder() {
    ImmutableMap<String, Integer> map = new Builder<String, Integer>().put("one", 1).buildOrThrow();
    assertMapEquals(map, "one", 1);
  }

  public void testBuilder() {

  public void testEmptyBuilder() {
    ImmutableMap<String, Integer> map = new Builder<String, Integer>().buildOrThrow();
    assertEquals(Collections.<String, Integer>emptyMap(), map);
  }

  public void testSingletonBuilder() {
    ImmutableMap<String, Integer> map = new Builder<String, Integer>().put("one", 1).buildOrThrow();
    assertMapEquals(map, "one", 1);
  }

  public void testBuilder() {

      ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
      for (Entry<String, String> entry : entries) {
        builder.put(entry.getKey(), entry.getValue());
      }
      return builder.buildOrThrow();
    }
  }

  public static class ImmutableMapCopyOfGenerator extends TestStringMapGenerator {
    @Override
    protected Map<String, String> create(Entry<String, String>[] entries) {

     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate keys. The {@code build()} method will soon be
     * deprecated.
     *
     * @throws IllegalArgumentException if duplicate keys were added
     */
    public ImmutableMap<K, V> build() {
      return buildOrThrow();
    }

    /**

        }
        return builder.buildOrThrow();
      }
    },
    BUILDER_PUT_ENTRIES_ONE_BY_ONE {
      @Override
      public Map<Object, Object> create(List<?> keys) {
        ImmutableMap.Builder<Object, Object> builder = ImmutableMap.builder();
        for (Object k : keys) {
          builder.put(Maps.immutableEntry(k, "dummy value"));
        }
        return builder.buildOrThrow();
      }
    },

        builder.putAll(sourceMap);
        return builder.buildOrThrow();
      }
    },
    BUILDER_PUT_ALL_ENTRIES {
      @Override
      public ImmutableBiMap<Object, Object> create(List<Entry<?, ?>> entries) {
        return ImmutableBiMap.builder().putAll(entries).buildOrThrow();
      }
    },
    FORCE_JDK {
      @Override

      ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
      for (Entry<String, String> entry : entries) {
        builder.put(entry.getKey(), entry.getValue());
      }
      return builder.buildOrThrow();
    }
  }

  public static class ImmutableMapCopyOfGenerator extends TestStringMapGenerator {
    @Override
    protected Map<String, String> create(Entry<String, String>[] entries) {

    @Nullable Object[] alternatingKeysAndValues;
    int size;
    boolean entriesUsed;
    /**
     * If non-null, a duplicate key we found in a previous buildKeepingLast() or buildOrThrow()
     * call. A later buildOrThrow() can simply report this duplicate immediately.
     */
    @Nullable DuplicateKey duplicateKey;

    /**

    }
    this.rowMap = rowBuilder.buildOrThrow();

    ImmutableMap.Builder<C, ImmutableMap<R, V>> columnBuilder =
        new ImmutableMap.Builder<>(columns.size());
    for (Entry<C, Map<R, V>> col : columns.entrySet()) {
      columnBuilder.put(col.getKey(), ImmutableMap.copyOf(col.getValue()));
    }
    this.columnMap = columnBuilder.buildOrThrow();
  }

  @Override

    }

    @Override
    public ImmutableBiMap<K, V> build() {
      return buildOrThrow();
    }

    @Override
    public ImmutableBiMap<K, V> buildOrThrow() {
      ImmutableMap<K, V> map = super.buildOrThrow();
      if (map.isEmpty()) {
        return of();
      }
      return new RegularImmutableBiMap<K, V>(super.buildOrThrow());
    }

    @Override
    ImmutableBiMap<K, V> buildJdkBacked() {