Does an OOP design that uses a Design by Contract mean the designer is using interfaces to create a "contract." The term "contract" is used quite often when discussing OOP interfaces, so I didn't know if these were talking about the same concept when using the word "Contract."
What I want to do in one of my designs is to force the class sending a message to do so based upon implementing an interface. For example,
public MyClass(IMyInterface something)
this.someKindOfThing = something;