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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_vcs_root(path):

 """Return VCS root directory path
 Return None if path is not within a supported VCS repository"""

    previous_path = path
    while get_vcs_info(path) is None:
        path = abspardir(path)
        if path == previous_path:
            return
        else:
            previous_path = path
    return osp.abspath(path)