Method init_request

tests/query/equal_query_test.cc:49–54

 private:
  void init_request() {
    request_ = new (std::nothrow) GetDocumentRequest();
    request_->set_collection_name(collection_);
    request_->set_debug_mode(false);
    request_->set_primary_key(1);
  }

  void init_response() {
    response_ = new (std::nothrow) GetDocumentResponse();