Interface segregation principle

up:: SOLID Split up the parent classes into ways that make sense.

Do not keep too much defined data in the parent class.

Like having a machine class that can print, scan and fax. When you try to inherit OldFashionedPrinter from a base class but that can’t scan or fax, users of the API might be surprised when using fax.

Since there aren’t really interfaces in JavaScript, this isn’t so relevant.