====== Create and destroy objects ======
  * Static factory methods instead of constructors
  * Builder when faced with many constructor parameters
  * Singleton with private constructor or enum type
  * Enforce noninstantiability with private constructor
  * Avoid creating unnecessary objects
  * Eliminate obsolete object references
  * Avoid finalizers

====== Methods Common to All Objects ======
====== Classes and Interfaces ======
===== Minimize the accessibility of classes and members =====
  * Information hiding / encapsulation for decoupling: Modules only communicate through APIs, implementation details are hidden
  * Rule: Make each class / member as inaccessible as possible.
  * Package-private: part of implementation, not API.
    * If pp class only used by one class => private nested class 
  * Protected/Public: Support forever
  * Private and package private members still can leak into API if class implements Serializable
  * "Acceptable" to make private member package-private to test it (but not further)
  * public static final fields FIELD_NAME only should contain immutable or primitive objects, no array
  * clone array / unmodifiableList for private static array accessors
  * In public classes, use accessor methods, not public fields
===== Minimize mutability =====

==== Immutable class ====
  * No methods that modify object's state
  * Final class (not extensible)
  * Final fields
  * Private fields
  * Exclusive access to mutable components

===== Composition over inheritance  =====