class JsonListener {
  private:

  public:

    virtual void whitespace(char c) = 0;

    virtual void startDocument() = 0;

    virtual void key(String key) = 0;

    virtual void value(String value) = 0;

    virtual void endArray() = 0;

    virtual void endObject() = 0;

    virtual void endDocument() = 0;

    virtual void startArray() = 0;

    virtual void startObject() = 0;

};