How to use the oauth2client.util function in oauth2client

@util.positional(2)
def flow_from_clientsecrets(filename, scope, redirect_uri=None,
                            message=None, cache=None, login_hint=None,
                            device_uri=None):
  """Create a Flow from a clientsecrets file.

  Will create the right kind of Flow based on the contents of the clientsecrets
  file or will raise InvalidClientSecretsError for unknown types of Flows.

  Args:
    filename: string, File name of client secrets.
    scope: string or iterable of strings, scope(s) to request.
    redirect_uri: string, Either the string 'urn:ietf:wg:oauth:2.0:oob' for
      a non-web-based application, or a URI that handles the callback from
      the authorization server.
    message: string, A friendly string to display to the user if the
      clientsecrets file is missing or invalid. If message is provided then

  @util.positional(4)
  def __init__(self,
               service_account_name,
               private_key,
               scope,
               private_key_password='notasecret',
               user_agent=None,
               token_uri=GOOGLE_TOKEN_URI,
               revoke_uri=GOOGLE_REVOKE_URI,
               **kwargs):
    """Constructor for SignedJwtAssertionCredentials.

    Args:
      service_account_name: string, id for account, usually an email address.
      private_key: string, private key in PKCS12 or PEM format.
      scope: string or iterable of strings, scope(s) of the credentials being
        requested.

  @util.positional(1)
  def step1_get_device_and_user_codes(self, http=None):
    """Returns a user code and the verification URL where to enter it

    Returns:
      A user code as a string for the user to authorize the application
      An URL as a string where the user has to enter the code
    """
    if self.device_uri is None:
      raise ValueError('The value of device_uri must not be None.')

    body = urllib.urlencode({
        'client_id': self.client_id,
        'scope': self.scope,
    })
    headers = {
        'content-type': 'application/x-www-form-urlencoded',

if error:
          errormsg = self.request.get('error_description', error)
          self.response.out.write(
              'The authorization request failed: %s' % _safe_html(errormsg))
        else:
          user = users.get_current_user()
          decorator._create_flow(self)
          credentials = decorator.flow.step2_exchange(self.request.params)
          StorageByKeyName(
              CredentialsModel, user.user_id(), 'credentials').put(credentials)
          redirect_uri = _parse_state_value(str(self.request.get('state')),
                                            user)

          if decorator._token_response_param and credentials.token_response:
            resp_json = simplejson.dumps(credentials.token_response)
            redirect_uri = util._add_query_parameter(
                redirect_uri, decorator._token_response_param, resp_json)

          self.redirect(redirect_uri)

  @util.positional(2)
  def __init__(self, scope, **kwargs):
    """Constructor for AppAssertionCredentials

    Args:
      scope: string or iterable of strings, scope(s) of the credentials being
        requested.
    """
    self.scope = util.scopes_to_string(scope)
    self.kwargs = kwargs

    # Assertion type is no longer used, but still in the parent class signature.
    super(AppAssertionCredentials, self).__init__(None)

"""Get a Storage instance for a credential.

  Args:
    filename: The JSON file storing a set of credentials
    client_id: The client_id for the credential
    user_agent: The user agent for the credential
    scope: string or iterable of strings, Scope(s) being requested
    warn_on_readonly: if True, log a warning if the store is readonly

  Returns:
    An object derived from client.Storage for getting/setting the
    credential.
  """
  # Recreate the legacy key with these specific parameters
  key = {'clientId': client_id, 'userAgent': user_agent,
         'scope': util.scopes_to_string(scope)}
  return get_credential_storage_custom_key(
      filename, key, warn_on_readonly=warn_on_readonly)

redirect_uri: string, Either the string 'urn:ietf:wg:oauth:2.0:oob' for
        a non-web-based application, or a URI that handles the callback from
        the authorization server.
      user_agent: string, HTTP User-Agent to provide for this application.
      auth_uri: string, URI for authorization endpoint. For convenience
        defaults to Google's endpoints but any OAuth 2.0 provider can be used.
      token_uri: string, URI for token endpoint. For convenience
        defaults to Google's endpoints but any OAuth 2.0 provider can be used.
      revoke_uri: string, URI for revoke endpoint. For convenience
        defaults to Google's endpoints but any OAuth 2.0 provider can be used.
      **kwargs: dict, The keyword arguments are all optional and required
                        parameters for the OAuth calls.
    """
    self.client_id = client_id
    self.client_secret = client_secret
    self.scope = util.scopes_to_string(scope)
    self.redirect_uri = redirect_uri
    self.user_agent = user_agent
    self.auth_uri = auth_uri
    self.token_uri = token_uri
    self.revoke_uri = revoke_uri
    self.params = {
        'access_type': 'offline',
        'response_type': 'code',
    }
    self.params.update(kwargs)

_credentials_class: "Protected" keyword argument not typically provided to
        this constructor. A db or ndb Model class to hold credentials. Defaults
        to CredentialsModel.
      _credentials_property_name: "Protected" keyword argument not typically
        provided to this constructor. A string indicating the name of the field
        on the _credentials_class where a Credentials object will be stored.
        Defaults to 'credentials'.
      **kwargs: dict, Keyword arguments are be passed along as kwargs to the
        OAuth2WebServerFlow constructor.
    """
    self._tls = threading.local()
    self.flow = None
    self.credentials = None
    self._client_id = client_id
    self._client_secret = client_secret
    self._scope = util.scopes_to_string(scope)
    self._auth_uri = auth_uri
    self._token_uri = token_uri
    self._revoke_uri = revoke_uri
    self._user_agent = user_agent
    self._kwargs = kwargs
    self._message = message
    self._in_error = False
    self._callback_path = callback_path
    self._token_response_param = token_response_param
    self._storage_class = _storage_class
    self._credentials_class = _credentials_class
    self._credentials_property_name = _credentials_property_name

  @util.positional(2)
  def _prettyPrintSchema(self, schema, seen=None, dent=0):
    """Get pretty printed object prototype of schema.

    Args:
      schema: object, Parsed JSON schema.
      seen: list of string, Names of schema already seen. Used to handle
        recursive definitions.

    Returns:
      string, A string that contains a prototype object with
        comments that conforms to the given schema.
    """
    if seen is None:
      seen = []

    return _SchemaToStruct(schema, seen, dent=dent).to_str(self._prettyPrintByName)