Imports the domain.

def _get_space(self):
        """
        Imports the domain.
        """
        assert 'space' in self.config, 'The search space is NOT configured!'
        
        space_config = self.config['space']
        constraint_config = self.config['constraints']
        from ..core.task.space import Design_space
        return Design_space.fromConfig(space_config, constraint_config)