void* load(int id) {
    if (check_if_current_id_was_deleted(id)) {
        cerr << "Current data was deleted and no longer exists!";
        return nullptr;
    }
    FILE * data_file;
    size_t current_data_size = static_cast<size_t>(indexes[id].data_size);
    void* return_data = malloc(current_data_size);
    for (unsigned int i = 0; i < indexes[id].file_names.size(); i++) {
        const char* current_filename = indexes[id].file_names[i].c_str();
        long int start_reading_position = indexes[id].start_reading_positions[i];
        long int end_reading_position = indexes[id].end_reading_positions[i];
        size_t reading_bytes_number = static_cast<size_t>(end_reading_position - start_reading_position);

        data_file = fopen(current_filename, "a+b");
        void* current_read_data = malloc(reading_bytes_number);

        fseek(data_file, start_reading_position, 0);
        fread(current_read_data, 1, reading_bytes_number, data_file);

        memcpy((void*)((char*)return_data + (reading_bytes_number*i)), current_read_data, reading_bytes_number);

        free(current_read_data);

        fclose(data_file);
    }
    return return_data;
}