code: def handleRequestForUser(self, username, url):
          
          attempt = self.newAttemptForUser(username)
          account = self.accountByAddress(username)
          if account is None:
              # do we want to disclose this to the user?
              return
          email = self.getExternalEmail(account)
          if email is not None:
              self.sendEmail(url, attempt, email)
docs: User C{username} wants to reset their password.  Create an attempt
          item, and send them an email if the username is valid