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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 _parse_metadata(response):
    '''
    Extracts out resource metadata information.
    '''

    if response is None or response.headers is None:
        return None

    metadata = _dict()
    for key, value in response.headers.items():
        if key.lower().startswith('x-ms-meta-'):
            metadata[key[10:]] = _to_str(value)

    return metadata