def observe_reward_value(self, state_key, action_key):
        '''
        Compute the reward value.
        
        Args:
            state_key:              The key of state.
            action_key:             The key of action.
        
        Returns:
            Reward value.

        '''
        reward_value = 0.0
        if state_key in self.__state_action_list_dict:
            if action_key in self.__state_action_list_dict[state_key]:
                reward_value = 1.0

        return reward_value
Compute the reward value.
        
        Args:
            state_key:              The key of state.
            action_key:             The key of action.
        
        Returns:
            Reward value.