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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_user(uid):
 """ Returns a user from the DCOS Enterprise. It returns None if none exists. :param uid: user id :type uid: str :return: User :rtype: dict """

    try:
        acl_url = urljoin(_acl_url(), 'users/{}'.format(uid))
        r = http.get(acl_url)
        return r.json()
        # assert r.status_code == 201
    except DCOSHTTPException as e:
        if e.response.status_code == 400:
            return None
        else:
            raise