How to use the sentinelhub.config.SHConfig function in sentinelhub

def _config_with_environment_variables():
        """ Reads configuration parameters from environmental variables
        """
        config = SHConfig()
        for param in config.get_params():
            env_variable = param.upper()
            if os.environ.get(env_variable):
                setattr(config, param, os.environ.get(env_variable))
        config.save()
        return config

def _do_aws_request(request):
    """ Executes download request from AWS service
    :param request: A request
    :type request: DownloadRequest
    :return: Response of the request
    :rtype: dict
    :raises: AwsDownloadFailedException, ValueError
    """
    if SHConfig().aws_access_key_id and SHConfig().aws_secret_access_key:
        key_args = dict(aws_access_key_id=SHConfig().aws_access_key_id,
                        aws_secret_access_key=SHConfig().aws_secret_access_key)
    else:
        key_args = {}
    aws_service, _, bucket_name, url_key = request.url.split('/', 3)

    try:
        s3_client = boto3.Session().client(aws_service.strip(':'), **key_args)
        request.s3_client = s3_client  # Storing the client prevents warning about unclosed socket
        DownloadRequest.GLOBAL_AWS_CLIENT = s3_client
    except KeyError:  # Sometimes creation of client fails and we use the global client if it exists
        if DownloadRequest.GLOBAL_AWS_CLIENT is None:
            raise ValueError('Failed to create a client for download from AWS')
        s3_client = DownloadRequest.GLOBAL_AWS_CLIENT

    try:
        return s3_client.get_object(Bucket=bucket_name, Key=url_key, RequestPayer='requester')

def _do_aws_request(request):
    """ Executes download request from AWS service
    :param request: A request
    :type request: DownloadRequest
    :return: Response of the request
    :rtype: dict
    :raises: AwsDownloadFailedException, ValueError
    """
    if SHConfig().aws_access_key_id and SHConfig().aws_secret_access_key:
        key_args = dict(aws_access_key_id=SHConfig().aws_access_key_id,
                        aws_secret_access_key=SHConfig().aws_secret_access_key)
    else:
        key_args = {}
    aws_service, _, bucket_name, url_key = request.url.split('/', 3)

    try:
        s3_client = boto3.Session().client(aws_service.strip(':'), **key_args)
        request.s3_client = s3_client  # Storing the client prevents warning about unclosed socket
        DownloadRequest.GLOBAL_AWS_CLIENT = s3_client
    except KeyError:  # Sometimes creation of client fails and we use the global client if it exists
        if DownloadRequest.GLOBAL_AWS_CLIENT is None:
            raise ValueError('Failed to create a client for download from AWS')
        s3_client = DownloadRequest.GLOBAL_AWS_CLIENT

    try:
        return s3_client.get_object(Bucket=bucket_name, Key=url_key, RequestPayer='requester')
    except NoCredentialsError:

def __init__(self, base_url=None, instance_id=None):
        """
        :param base_url: base url of Sentinel Hub's OGC services. If `None`, the url specified in the configuration
                    file is taken.
        :type base_url: str or None
        :param instance_id: user's instance id granting access to Sentinel Hub's OGC services. If `None`, the instance
            ID specified in the configuration file is taken.
        :type instance_id: str or None
        """
        self.base_url = SHConfig().ogc_base_url if not base_url else base_url
        self.instance_id = SHConfig().instance_id if not instance_id else instance_id

        if not self.instance_id:
            raise ValueError('Instance ID is not set. '
                             'Set it either in request initialization or in configuration file. '

:type absolute_orbit: int
    :return: An iterator returning dictionaries with info provided by Sentinel Hub OpenSearch REST service
    :rtype: Iterator[dict]
    """
    if bbox and bbox.crs is not CRS.WGS84:
        bbox = bbox.transform(CRS.WGS84)

    url_params = _prepare_url_params(tile_id, bbox, end_date, start_date, absolute_orbit)
    url_params['maxRecords'] = SHConfig().max_opensearch_records_per_query

    start_index = 1

    while True:
        url_params['index'] = start_index

        url = '{}search.json?{}'.format(SHConfig().opensearch_url, urlencode(url_params))
        LOGGER.debug("URL=%s", url)

        response = get_json(url)
        for tile_info in response["features"]:
            yield tile_info

        if len(response["features"]) < SHConfig().max_opensearch_records_per_query:
            break
        start_index += SHConfig().max_opensearch_records_per_query

def get_base_url(self, force_http=False):
        """ Creates base URL path

        :param force_http: `True` if HTTP base URL should be used and `False` otherwise
        :type force_http: str
        :return: base url string
        :rtype: str
        """
        base_url = SHConfig().aws_metadata_url.rstrip('/') if force_http else 's3:/'
        aws_bucket = SHConfig().aws_s3_l1c_bucket if self.data_source is DataSource.SENTINEL2_L1C else \
            SHConfig().aws_s3_l2a_bucket

        return '{}/{}/'.format(base_url, aws_bucket)

def __init__(self, base_url=None, instance_id=None):
        """
        :param base_url: base url of Sentinel Hub's OGC services. If `None`, the url specified in the configuration
                    file is taken.
        :type base_url: str or None
        :param instance_id: user's instance id granting access to Sentinel Hub's OGC services. If `None`, the instance
            ID specified in the configuration file is taken.
        :type instance_id: str or None
        """
        self.base_url = SHConfig().ogc_base_url if not base_url else base_url
        self.instance_id = SHConfig().instance_id if not instance_id else instance_id

        if not self.instance_id:
            raise ValueError('Instance ID is not set. '
                             'Set it either in request initialization or in configuration file. '

LOGGER.debug('Successful download from %s', request.url)
            break
        except requests.RequestException as exception:
            try_num -= 1
            if try_num > 0 and (_is_temporal_problem(exception) or
                                (isinstance(exception, requests.HTTPError) and
                                 exception.response.status_code >= requests.status_codes.codes.INTERNAL_SERVER_ERROR) or
                                _request_limit_reached(exception)):
                LOGGER.debug('Download attempt failed: %s\n%d attempts left, will retry in %ds', exception,
                             try_num, SHConfig().download_sleep_time)
                sleep_time = SHConfig().download_sleep_time
                if _request_limit_reached(exception):
                    sleep_time = max(sleep_time, 60)
                time.sleep(sleep_time)
            else:
                if request.url.startswith(SHConfig().aws_metadata_url) and \
                        isinstance(exception, requests.HTTPError) and \
                        exception.response.status_code == requests.status_codes.codes.NOT_FOUND:
                    raise AwsDownloadFailedException('File in location %s is missing' % request.url)
                raise DownloadFailedException(_create_download_failed_message(exception, request.url))

    _save_if_needed(request, response_content)

    if request.return_data:
        return decode_data(response_content, request.data_type, entire_response=response)
    return None

def get_base_url(self, force_http=False):
        """ Creates base URL path

        :param force_http: `True` if HTTP base URL should be used and `False` otherwise
        :type force_http: str
        :return: base url string
        :rtype: str
        """
        base_url = SHConfig().aws_metadata_url.rstrip('/') if force_http else 's3:/'
        aws_bucket = SHConfig().aws_s3_l1c_bucket if self.data_source is DataSource.SENTINEL2_L1C else \
            SHConfig().aws_s3_l2a_bucket

        return '{}/{}/'.format(base_url, aws_bucket)

url_params = _prepare_url_params(tile_id, bbox, end_date, start_date, absolute_orbit)
    url_params['maxRecords'] = SHConfig().max_opensearch_records_per_query

    start_index = 1

    while True:
        url_params['index'] = start_index

        url = '{}search.json?{}'.format(SHConfig().opensearch_url, urlencode(url_params))
        LOGGER.debug("URL=%s", url)

        response = get_json(url)
        for tile_info in response["features"]:
            yield tile_info

        if len(response["features"]) < SHConfig().max_opensearch_records_per_query:
            break
        start_index += SHConfig().max_opensearch_records_per_query