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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 build_avatar_url(jid):
 """ Static method to build a gravatar url with the agent's JID Args: jid (aioxmpp.JID):
 an XMPP identifier Returns: str: an URL for the gravatar """

        digest = md5(str(jid).encode("utf-8")).hexdigest()
        return "http://www.gravatar.com/avatar/{md5}?d=monsterid".format(md5=digest)