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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 request_access_token(self, access_code):
        "Request access token from GitHub"
        token_response = request_session.post(
            "https://github.com/login/oauth/access_token",
            data={
                "client_id": self.oauth_client_id,
                "client_secret": self.oauth_client_secret,
                "code": access_code
            },
            headers={"Accept": "application/json"},
        )
        return helper_request_access_token(token_response.json())