Nick Swaggert, director of the Veteran Program at business consulting and staffing company Genesis 10 and a military veteran, said that, like in the military, rank matters when it comes to the person you're asking for a reference. A reference from your last company's C-suite might look impressive, but if that person has limited experience working with you, he or she might not have anything valuable to tell a potential employer. Therefore, it's important to prepare him or her for the conversation. [3 Subtle Things Successful Job Seekers Do Right]
Successful family planning programs listen to the different needs of clients and respond with strategies that expand informed, voluntary contraceptive choice: offering a range of affordable contraceptive methods; providing client-centered, comprehensive counseling; employing a variety of service delivery approaches; and ensuring continuous supplies of contraceptive commodities. Expanding individuals’ contraceptive choices supports increased and continuous contraceptive use, enabling more women and couples to realize their ambitions for themselves and their families and helping communities and nations achieve their development goals. This web feature and accompanying brief explore the rationale for expanding contraceptive choice.
In short, class invariants ensure that there will be some constraints in your class that will not get violated in normal use (and therefore, the class will not get in an inconsistent state). Preconditions mean that data given as input to a function/method must follow some constraints set and never violate them, and postconditions mean that a function/method output must follow the set constraints again without ever violating them. Contract conditions should never be violated during execution of a bug-free program, therefore design by contract is checked in practice in debug mode, while being disabled in releases , to maximize the developed system performance.