def run_iteration(self):
        '''Runs a single iteration of the ABC; employer phase -> probability
        calculation -> onlooker phase -> check positions
        '''

        self._employer_phase()
        self._calc_probability()
        self._onlooker_phase()
        self._check_positions()
Runs a single iteration of the ABC; employer phase -> probability
        calculation -> onlooker phase -> check positions