Both High level and low level modules should be
dependent on a common abstraction or interface
Usually most of class diagrams are designed from
top to bottom and but there is an OO principle “Be dependent on abstraction
instead of concrete classes” that
reverse this diagram and that is called dependency inversion.
High-level modules should not depend on low-level modules. Both should depend on abstractions.
Abstractions should not depend on details. Details should depend on abstractions.
