valuetype vt {  public short x;};valuetype base {  public short y;};valuetype derived : truncatable base {  public vt z;};valuetype node {  public node next;};interface iface {  /*   *   derived_var d = ...;   *   ...   *   iface->skipped_value (d, d->z());   * even when the server doesnt have a factory for derived it   * must be able to extract d->z() for the second parameter.   */  void skipped_value (in base b, in vt v);  /*   *   vt_var v = ...;   *   ...   *   iface->shared_parameter (v, v);   * on the server side this must result in v1 == v2 (same pointer).   */  void shared_parameter (in vt v1, in vt v2);  /*   * the transmitted valuetype graph must be isomorphic to the   * original valuetype graph. check this using a cyclic list.   */  void cyclic (in node n);};