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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 _init_credentials(self, oauth_token, oauth_token_secret):
        "Depending on the state passed in, get self._oauth up and running"
        if oauth_token and oauth_token_secret:
            if self.verified:
                # If provided, this is a fully verified set of
                # credentials. Store the oauth_token and secret
                # and initialize OAuth around those
                self._init_oauth(oauth_token, oauth_token_secret)

            else:
                # If provided, we are reconstructing an initalized
                # (but non-verified) set of public credentials.
                self.oauth_token = oauth_token
                self.oauth_token_secret = oauth_token_secret

        else:
            # This is a brand new set of credentials - we need to generate
            # an oauth token so it's available for the url property.
            oauth = OAuth1(
                self.consumer_key,
                client_secret=self.consumer_secret,
                callback_uri=self.callback_uri,
                rsa_key=self.rsa_key,
                signature_method=self._signature_method
            )

            url = self.base_url + REQUEST_TOKEN_URL
            headers = {'User-Agent': self.user_agent}
            response = requests.post(url=url, headers=headers, auth=oauth)
            self._process_oauth_response(response)