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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 fetch(url, body=None, headers=None):
 """Invoke the fetch method on the default fetcher. Most users should need only this method. @raises Exception: any exceptions that may be raised by the default fetcher """

    fetcher = getDefaultFetcher()
    return fetcher.fetch(url, body, headers)