Some notes about Pluralsigth course: Encapsulation and SOLID by Mark Seemann

 - CQS for getting code simpler
 - More reading then writing code
 - Hide information (not public setters)
 - Not invalid states
 - Fail Fats
 - Never return null
 - SOLID, for making code more maintainable
rigidity: design difficult to change, easy to break
viscosity: no needed complexity, overkill design (simplicity)
 - Developers have  a tendency  to attempt  to solve specific problems with general solutions by Greg Young
 - Instead of being general code should be specific. by Greg Young
 - Following the SRP, each concrete class is very specific
 - Abstraction is the elimination of the irrelevant and the amplification of the essential by Robert C. Martin
 - Start with concrete behavior and discover abstractions as commonality emerges by rules of three
 - Favor composition over inheritance for example by strategy, decorator, ... patterns.
 - Don´t override inherited base class methods (Liskov Substitution Principle)
 - Implements all methods of inherited interface, don´t remove features from inherited class throwing NotSupportedException (Liskov Substitution Principle)
 - Prefer a tons of small, concrete, trial, simple and granular classes with a low level of abstraction, than a few classes with a lots of code.
 - Client should not depend on method that they do not use (Interface segregation principal)
 - Small interface with one operation.