How to use the solarforecastarbiter.io.reference_observations.common function in solarforecastarbiter

Since variables are labelled with an integer instrument
    number, Observations are named with their variable and
    instrument number found in the source files.

    e.g. A SRML file contains two columns labelled, 1001, and
    1002. These columns represent GHI at instrument 1 and
    instrument 2 respectively. The `pvlib.iotools` package
    converts these to 'ghi_1' and 'ghi_2' for us. We use these
    labels to differentiate between measurements recorded by
    different instruments.
    """
    # Request ~month old data at initialization to ensure we get a response.
    start = pd.Timestamp.now() - pd.Timedelta('30 days')
    end = start
    try:
        extra_params = common.decode_extra_parameters(site)
    except ValueError:
        logger.warning('Cannot create reference observations at MIDC site '
                       f'{site.name}, missing required parameters.')
        return
    # use site name without network here to build
    # a name with the original column label rather than
    # the SFA variable
    site_name = common.site_name_no_network(site)
    try:
        site_df = fetch(api, site, start, end)
    except error.HTTPError:
        logger.error('Could not find data to create observations '
                     f'for SRML site {site_name}.')
        return
    else:
        if site_df is None:

The end of the period to request data for.
    realtime : bool
        Whether or not to look for realtime data. Note that this data is
        raw, unverified data from the instruments.

    Returns
    -------
    data : pandas.DataFrame
        All of the requested data concatenated into a single DataFrame.
    """
    if realtime:
        url_format = REALTIME_URL
    else:
        url_format = ARCHIVE_URL
    # load extra parameters for api arguments.
    extra_params = common.decode_extra_parameters(site)
    abbreviation = extra_params['network_api_abbreviation']
    single_day_dfs = []
    for day in pd.date_range(start, end):
        filename = url_format.format(abrv=abbreviation,
                                     year=day.year,
                                     year_2d=day.strftime('%y'),
                                     jday=day.strftime('%j'))
        logger.info(f'Requesting data for SOLRAD site {site.name}'
                    f' on {day.strftime("%Y%m%d")}.')
        try:
            # Only get dataframe from the returned tuple
            solrad_day = iotools.read_solrad(filename)
        except URLError:
            logger.warning(f'Could not retrieve SOLRAD data for site '
                           f'{site.name} on {day.strftime("%Y%m%d")}.')
            logger.debug(f'Failed SOLRAD URL: {filename}.')

Returns
    -------
    datamodel.Site
        The created site object.
    """
    # get a reference to network before we serialize extra_parameters
    network = site['extra_parameters']['network']
    network_handler = NETWORKHANDLER_MAP.get(network)
    if network_handler is None:
        logger.warning(f'Unrecognized network, {network} on Site '
                       f'{site["name"]} Observations cannot be '
                       'automatically generated.')
        return
    site.update({'extra_parameters': json.dumps(site['extra_parameters'])})
    site_name = f"{network} {common.clean_name(site['name'])}"
    existing = common.existing_sites(api)
    if site_name in existing:
        logger.info('Site, %s, already exists', site_name)
        created = existing[site_name]
    else:
        site['name'] = site_name
        site_to_create = Site.from_dict(site)
        try:
            created = api.create_site(site_to_create)
        except HTTPError as e:
            logger.error(f"Failed to create Site {site['name']}.")
            logger.debug(f'HTTP Error: {e.response.text}')
            return False
        else:
            logger.info(f'Created Site {created.name} successfully.')
    network_handler.initialize_site_observations(api, created)
    try:

def get_filename(site, year):
    """Get the applicable file name for CRN a site on a given date.
    """
    extra_params = common.decode_extra_parameters(site)
    network_api_id = extra_params['network_api_id']
    filename = f'{year}/CRNS0101-05-{year}-{network_api_id}.txt'
    return CRN_URL + filename

at each SOLRAD site between start and end.

    api : solarforecastarbiter.io.api.APISession
        An active Reference user session.
    sites : list of solarforecastarbiter.datamodel.Site
        List of all reference sites as Objects
    observations : list of solarforecastarbiter.datamodel.Observation
        List of all reference observations.
    start : datetime
        The beginning of the period to request data for.
    end : datetime
        The end of the period to request data for.
    """
    solrad_sites = common.filter_by_networks(sites, 'NOAA SOLRAD')
    for site in solrad_sites:
        common.update_site_observations(
            api, fetch, site, observations, start, end)

Returns
    -------
    datamodel.Site
        The created site object.
    """
    # get a reference to network before we serialize extra_parameters
    network = site['extra_parameters']['network']
    network_handler = NETWORKHANDLER_MAP.get(network)
    if network_handler is None:
        logger.warning(f'Unrecognized network, {network} on Site '
                       f'{site["name"]} Observations cannot be '
                       'automatically generated.')
        return
    site.update({'extra_parameters': json.dumps(site['extra_parameters'])})
    site_name = f"{network} {common.clean_name(site['name'])}"
    existing = common.existing_sites(api)
    if site_name in existing:
        logger.info('Site, %s, already exists', site_name)
        created = existing[site_name]
    else:
        site['name'] = site_name
        site_to_create = Site.from_dict(site)
        try:
            created = api.create_site(site_to_create)
        except HTTPError as e:
            logger.error(f"Failed to create Site {site['name']}.")
            logger.debug(f'HTTP Error: {e.response.text}')
            return False
        else:
            logger.info(f'Created Site {created.name} successfully.')
    network_handler.initialize_site_observations(api, created)

def adjust_site_parameters(site):
    """Inserts modeling parameters for sites with pv measurments

    Parameters
    ----------
    site: dict

    Returns
    -------
    dict
        Copy of inputs plus a new key 'modeling_parameters'.
    """
    return common.apply_json_site_parameters(DEFAULT_SITEFILE, site)