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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_version_from_scm(path=None):
 """Get the current version string of this package using SCM tool. Parameters path : None or string, optional The SCM checkout path (default is current directory) Returns ------- version : string The version string for this package """

    if is_git(path):
        return 'git', get_git_version(path)
    elif is_svn(path):
        return 'svn', get_svn_version(path)
    return None, None