checkNonnegative(expectedKeys, "expectedKeys");
    return new MultimapBuilderWithKeys<@Nullable Object>() {
      @Override
      <K extends @Nullable Object, V extends @Nullable Object> Map<K, Collection<V>> createMap() {
        return Platform.newHashMapWithExpectedSize(expectedKeys);
      }
    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *

    checkNonnegative(expectedKeys, "expectedKeys");
    return new MultimapBuilderWithKeys<@Nullable Object>() {
      @Override
      <K extends @Nullable Object, V extends @Nullable Object> Map<K, Collection<V>> createMap() {
        return Platform.newHashMapWithExpectedSize(expectedKeys);
      }
    };
  }

  /**
   * Uses a hash table to map keys to value collections.
   *