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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 path_to_pattern(path, metadata=None):
 """ Remove source information from path when using chaching Returns None if path is not str Parameters path : str Path to data optionally containing format_strings metadata : dict, optional Extra arguments to the class, contains any cache information Returns ------- pattern : str Pattern style path stripped of everything to the left of cache regex. """

    if not isinstance(path, str):
        return

    pattern = path
    if metadata:
        cache = metadata.get('cache')
        if cache:
            regex = next(c.get('regex') for c in cache if c.get('argkey') == 'urlpath')
            pattern = pattern.split(regex)[-1]
    return pattern