README

Item 1: Consider static factory methods instead of constructors

Item 2: Consider a builder when faced with many constructor parameters

Item 3: Enforce the singleton property with a private constructor or an enum type

Item 4: Enforce noninstantiability with a private constructor

Item 5: Prefer dependency injection to hardwiring resources
 -> Classical by the use of constructor (or static factory, builder) or better by the use of a
    dependency injection framework
    Other variant with Java 8 use a supplier
    Mosaic create(Supplier<? extends> tileFactory) { ... }

Item 6: Avoid creating unnecessary objects
      Like String s = new String("k");
      Boolean.valueOf("true") better than new Boolean(true)


  https://www.gamedev.net/articles/programming/general-and-gameplay-programming/finite-state-machines-and-regular-expressions-r3176/

Item 8: Avoid finalizers and cleaners
  -> There is no guarantee that at which time they are called (if at all).
     Implement AutoClosable instead if you want that the client

Item 7: Eliminate obsolete object references
Have a look at Stack.java, do you find the obsolete reference

Item 9: Prefer try-with-resources to try-f inally
{code}
try (InputStream in = new FileInputStream(src); OutputStream out = new FileOutputStream(dst)) {
   ...
}}
{code}

item10