code: def select_action(self, next_action_arr, next_q_arr):
          '''
          Select action by Q(state, action).
  
          Args:
              next_action_arr:        `np.ndarray` of actions.
              next_q_arr:             `np.ndarray` of Q-Values.
  
          Retruns:
              Tuple(`np.ndarray` of action., Q-Value)
          '''
          key_arr = self.select_action_key(next_action_arr, next_q_arr)
          return next_action_arr[key_arr], next_q_arr[key_arrf select_action(self, next_action_arr, next_q_arr):
          '''
          Select action by Q(state, action).
  
          Args:
              next_action_arr:        `np.ndarray` of actions.
              next_q_arr:             `np.ndarray` of Q-Values.
  
          Retruns:
              Tuple(`np.ndarray` of action., Q-Value)
          '''
          key_arr = self.select_action_key(next_action_arr, next_q_arr)
          return next_action_arr[key_arr], next_q_arr[key_arr]
docs: Select action by Q(state, action).
  
          Args:
              next_action_arr:        `np.ndarray` of actions.
              next_q_arr:             `np.ndarray` of Q-Values.
  
          Retruns:
              Tuple(`np.ndarray` of action., Q-Value)