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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _process_oauth_response(self, response):
        "Extracts the fields from an oauth response"
        if response.status_code == 200:
            credentials = parse_qs(response.text)

            # Initialize the oauth credentials
            self._init_oauth(
                credentials.get('oauth_token')[0],
                credentials.get('oauth_token_secret')[0]
            )

            # If tokens are refreshable, we'll get a session handle
            self.oauth_session_handle = credentials.get(
                    'oauth_session_handle', [None])[0]

            # Calculate token/auth expiry
            oauth_expires_in = credentials.get(
                    'oauth_expires_in',
                    [OAUTH_EXPIRY_SECONDS])[0]
            oauth_authorisation_expires_in = credentials.get(
                    'oauth_authorization_expires_in',
                    [OAUTH_EXPIRY_SECONDS])[0]

            self.oauth_expires_at = datetime.datetime.now() + \
                                    datetime.timedelta(seconds=int(
                                        oauth_expires_in))
            self.oauth_authorization_expires_at = \
                                    datetime.datetime.now() + \
                                    datetime.timedelta(seconds=int(
                                        oauth_authorisation_expires_in))
        else:
            self._handle_error_response(response)