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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 get_token(access_token=None, refresh_token=None):
 """Load an access token. Add support for personal access tokens compared to flask-oauthlib. If the access token is ``None``, it looks for the refresh token. :param access_token: The access token. (Default: ``None``) :param refresh_token: The refresh token. (Default: ``None``) :returns: The token instance or ``None``. """

    if access_token:
        t = Token.query.filter_by(access_token=access_token).first()
        if t and t.is_personal and t.user.active:
            t.expires = datetime.utcnow() + timedelta(
                seconds=int(current_app.config.get(
                    'OAUTH2_PROVIDER_TOKEN_EXPIRES_IN'
                ))
            )
    elif refresh_token:
        t = Token.query.join(Token.client).filter(
            Token.refresh_token == refresh_token,
            Token.is_personal == False,  # noqa
            Client.is_confidential == True,
        ).first()
    else:
        return None
    return t if t and t.user.active else None