/**
   * @param in Object input.
   * @return Read collection.
   * @throws IOException If failed.
   * @throws ClassNotFoundException If failed.
   */
  private Collection<Object> readFieldsCollection(ObjectInput in)
      throws IOException, ClassNotFoundException {
    assert fields;

    int size = in.readInt();

    if (size == -1) return null;

    Collection<Object> res = new ArrayList<>(size);

    for (int i = 0; i < size; i++) {
      int size0 = in.readInt();

      Collection<Object> col = new ArrayList<>(size0);

      for (int j = 0; j < size0; j++) col.add(in.readObject());

      assert col.size() == size0;

      res.add(col);
    }

    assert res.size() == size;

    return res;
  }
  /** {@inheritDoc} */
  @Override
  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
    GridBiTuple<GridCacheContext, String> t = stash.get();

    t.set1((GridCacheContext) in.readObject());
    t.set2(in.readUTF());
  }
 /** {@inheritDoc} */
 @Override
 public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
   key = (K) in.readObject();
   val = (V) in.readObject();
 }