@classmethod
def clone(cls, objective, model=None, **kwargs):
    """
        Make a copy of an objective. The objective being copied can be of the same type or belong to
        a different solver interface.

        Example
        ----------
        >>> new_objective = Objective.clone(old_objective)
        """
    return cls(cls._substitute_variables(objective, model=model), name=
        objective.name, direction=objective.direction, sloppy=True, **kwargs)
