The cases which have been considered in the paragraphs which have gone immediately before have been ones in which there has been state legislation impairing contracts created by or resting upon prior statutes. In these cases the federal court has sought to determine for itself whether these earlier laws were constitutional as tested by the state constitutions of the States whose legislatures enacted them. "We have now to turn to a class of cases in which the federal Supreme Court, without considering as an independent proposition the constitutionality of state laws, has refused to follow the decisions of the highest state courts holding them to be void, when to do so would be to render null contracts which have been entered into, the parties thereto relying in good faith upon the validity of such laws. Here, it is to be observed, the federal tribunal has not said that the state laws in question are to be treated as continuously constitutional and valid, that is, valid in futuro, the decisions of the state courts to the contrary notwithstanding, but only that, contracts which have been entered into in reliance upon them are not to be affected by their unconstitutionality. Thus, in effect, the position is taken that laws which are unconstitutional as judged by the state constitutions, and, therefore, void, may have a de facto character that will furnish a legal basis for contracts founded upon them.