For example, let's say that you want to have a *path operation* that allows to update items, and returns HTTP status codes of 200 "OK" when successful.

But you also want it to accept new items. And when the items didn't exist before, it creates them, and returns an HTTP status code of 201 "Created".

    return new ImmutableMapKeySet<>(this);
  }

  @Override
  public void forEach(BiConsumer<? super K, ? super V> action) {
    checkNotNull(action);
    for (Entry<K, V> entry : entries) {
      action.accept(entry.getKey(), entry.getValue());
    }
  }

  @Override
  boolean isHashCodeFast() {
    return true;
  }

  @Override
  public int hashCode() {
    return hashCode;
  }

     *
     * @param file the SMB file to test for inclusion
     * @return whether the given file should be included
     * @throws SmbException if an error occurs while accessing the file
     */
    boolean accept(SmbFile file) throws SmbException;

     * @param name the name of the file
     * @return whether the given filename should be included
     * @throws SmbException if an SMB error occurs during evaluation
     */
    boolean accept(SmbFile dir, String name) throws SmbException;

    public AccessTokenCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsAccessTokenCB cb = this;
        cb.query().docMeta().setId_Equal(id);
        return (AccessTokenCB) this;
    }

    @Override
    public void acceptPrimaryKeyMap(Map<String, ? extends Object> primaryKeyMap) {
        acceptPK((String) primaryKeyMap.get("_id"));
    }

    public FailureUrlCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsFailureUrlCB cb = this;
        cb.query().docMeta().setId_Equal(id);
        return (FailureUrlCB) this;
    }

    @Override
    public void acceptPrimaryKeyMap(Map<String, ? extends Object> primaryKeyMap) {
        acceptPK((String) primaryKeyMap.get("_id"));
    }

    public RelatedContentCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsRelatedContentCB cb = this;
        cb.query().docMeta().setId_Equal(id);
        return (RelatedContentCB) this;
    }

    @Override
    public void acceptPrimaryKeyMap(Map<String, ? extends Object> primaryKeyMap) {
        acceptPK((String) primaryKeyMap.get("_id"));
    }

    public RoleTypeCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsRoleTypeCB cb = this;
        cb.query().docMeta().setId_Equal(id);
        return (RoleTypeCB) this;
    }

    @Override
    public void acceptPrimaryKeyMap(Map<String, ? extends Object> primaryKeyMap) {
        acceptPK((String) primaryKeyMap.get("_id"));
    }

    public ClickLogCB acceptPK(String id) {
        assertObjectNotNull("id", id);
        BsClickLogCB cb = this;
        cb.query().docMeta().setId_Equal(id);
        return (ClickLogCB) this;
    }

    @Override
    public void acceptPrimaryKeyMap(Map<String, ? extends Object> primaryKeyMap) {
        acceptPK((String) primaryKeyMap.get("_id"));
    }

    } else {
      return unsafeDoBackward(b);
    }
  }

  /*
   * LegacyConverter violates the contract of Converter by allowing its doForward and doBackward
   * methods to accept null. We could avoid having unchecked casts in Converter.java itself if we
   * could perform a cast to LegacyConverter, but we can't because it's an internal-only class.
   *