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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 identify_repo(repo_url):
 """Determine if `repo_url` should be treated as a URL to a git or hg repo. Repos can be identified by prepending "hg+" or "git+" to the repo URL. :param repo_url: Repo URL of unknown type. :returns: ('git', repo_url), ('hg', repo_url), or None. """

    repo_url_values = repo_url.split('+')
    if len(repo_url_values) == 2:
        repo_type = repo_url_values[0]
        if repo_type in ["git", "hg"]:
            return repo_type, repo_url_values[1]
        else:
            raise UnknownRepoType
    else:
        if 'git' in repo_url:
            return 'git', repo_url
        elif 'bitbucket' in repo_url:
            return 'hg', repo_url
        else:
            raise UnknownRepoType