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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 pushover(message, token, user, title="JCVI: Job Monitor", \ priority=0, timestamp=None):
 """ pushover.net python API <https://pushover.net/faq#library-python> """

    assert -1 <= priority <= 2, \
            "Priority should be an int() between -1 and 2"

    if timestamp == None:
        from time import time
        timestamp = int(time())

    retry, expire = (300, 3600) if priority == 2 \
            else (None, None)

    conn = HTTPSConnection("api.pushover.net:443")
    conn.request("POST", "/1/messages.json",
      urlencode({
          "token": token,
          "user": user,
          "message": message,
          "title": title,
          "priority": priority,
          "timestamp": timestamp,
          "retry": retry,
          "expire": expire,
      }), { "Content-type": "application/x-www-form-urlencoded" })
    conn.getresponse()