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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 run(self):
 """ This defines the sequence of actions that are taken when the barrier concurrency state is executed :return: """

        logger.debug("Starting execution of {0}{1}".format(self, " (backwards)" if self.backward_execution else ""))
        self.setup_run()

        # data to be accessed by the decider state
        child_errors = {}
        final_outcomes_dict = {}
        decider_state = self.states[UNIQUE_DECIDER_STATE_ID]

        try:
            concurrency_history_item = self.setup_forward_or_backward_execution()
            self.start_child_states(concurrency_history_item, decider_state)

            # print("bcs1")

            #######################################################
            # wait for all child threads to finish
            #######################################################
            for history_index, state in enumerate(self.states.values()):
                # skip the decider state
                if state is not decider_state:
                    self.join_state(state, history_index, concurrency_history_item)
                    self.add_state_execution_output_to_scoped_data(state.output_data, state)
                    self.update_scoped_variables_with_output_dictionary(state.output_data, state)
                    # save the errors of the child state executions for the decider state
                    if 'error' in state.output_data:
                        child_errors[state.state_id] = (state.name, state.output_data['error'])
                    final_outcomes_dict[state.state_id] = (state.name, state.final_outcome)

            # print("bcs2")

            #######################################################
            # handle backward execution case
            #######################################################
            if self.backward_execution:
                # print("bcs2.1.")
                return self.finalize_backward_execution()
            else:
                # print("bcs2.2.")
                self.backward_execution = False

            # print("bcs3")

            #######################################################
            # execute decider state
            #######################################################
            decider_state_error = self.run_decider_state(decider_state, child_errors, final_outcomes_dict)

            # print("bcs4")

            #######################################################
            # handle no transition
            #######################################################
            transition = self.get_transition_for_outcome(decider_state, decider_state.final_outcome)
            if transition is None:
                # final outcome is set here
                transition = self.handle_no_transition(decider_state)
            # if the transition is still None, then the child_state was preempted or aborted, in this case return
            decider_state.state_execution_status = StateExecutionStatus.INACTIVE

            # print("bcs5")

            if transition is None:
                self.output_data["error"] = RuntimeError("state aborted")
            else:
                if decider_state_error:
                    self.output_data["error"] = decider_state_error
                self.final_outcome = self.outcomes[transition.to_outcome]

            # print("bcs6")

            return self.finalize_concurrency_state(self.final_outcome)

        except Exception as e:
            logger.error("{0} had an internal error: {1}\n{2}".format(self, str(e), str(traceback.format_exc())))
            self.output_data["error"] = e
            self.state_execution_status = StateExecutionStatus.WAIT_FOR_NEXT_STATE
            return self.finalize(Outcome(-1, "aborted"))