'Add a single host to the model. Return None.'

def _add_single_host_to_model(self, host):

    vuln_count = host.getVulnAmount()
    (os_icon, os_str) = self.__decide_icon(host.getOS())
    display_str = str(host)
    host_iter = self.model.append([host.id, os_icon, os_str, display_str, vuln_count])
    self.host_id_to_iter[host.id] = host_iter
    self.host_amount_in_model += 1
