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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 _ExtractGMailSearchQuery(self, url):
 """Extracts a search query from a GMail search URL. GMail: https://mail.google.com/mail/u/0/#search/query[/?] Args: url (str):
 URL. Returns: str: search query or None if no query was found. """

    if 'search/' not in url:
      return None

    _, _, line = url.partition('search/')
    line, _, _ = line.partition('/')
    line, _, _ = line.partition('?')

    return line.replace('+', ' ')