I concur except that I think any decree for performance under future as well as under present conditions is subject to modification to adapt it to the future conditions. Conditions will change and sometimes render enforcement impracticable, the court will not insist upon an impracticable performance, of course, but will act according to conditions as they may be, and thus, whether we avow it or not, the decree will be modified or suspended; and it seems to me this limitation should be recognized in the rule. Compare Emergency Hospital v. Stevens,146 Md. 159, 166; 23 Michigan Law Rev. 382.