private Serialization() {}

  /**
   * Reads a count corresponding to a serialized map, multiset, or multimap. It returns the size of
   * a map serialized by {@link #writeMap(Map, ObjectOutputStream)}, the number of distinct elements
   * in a multiset serialized by {@link #writeMultiset(Multiset, ObjectOutputStream)}, or the number
   * of distinct keys in a multimap serialized by {@link #writeMultimap(Multimap,
   * ObjectOutputStream)}.
   */