anchor.diff:  as the current Subject has *at least one* of the given roles.
   
   === Restrict entity classes
  -Not every read or insert needs a specialized Transaction. If you call read or insert on the Persistence
  -interface a generic Transaction is instantiated:
  -[source,java,title="DelegatePersistence.java"]
  +Not every read or insert needs a specialized Transaction. If you call read or insert on the Backend a generic Transaction is instantiated:
  +[source,java,title="Backend.java"]
   ----
   	[..]
   	
  -	@Override
  -	public <T> List<T> read(Class<T> clazz, Criteria criteria, int maxResults) {
  -		List<T> result = backend.execute(new ReadCriteriaTransaction<T>(clazz, criteria, maxResults));
  +	public static <T> List<T> read(Class<T> clazz, Criteria criteria, int maxResults) {
  +		List<T> result = getInstance().execute(new ReadCriteriaTransaction<T>(clazz, criteria, maxResults));
   		return result;
   	}
   ----
   
  -To restrict access on entities their classes can be annotated (TODO better example):
  +To restrict access on entities their classes can be annotated
   [source,java]
   ----
   @Role("RoleB")
  
positive.code: Note that packages don't inherit there roles from their parent. This would lead to a error-prone complexity.
  
  == Authorization configuration
  As for things this configuration is done via application properties. If the property MjUserFile is defined a
  TextFileAuthorizaion is installed.
  
  If no MjUserFile property is specified Minimal-J is look for the property MjAuthorization. It should provide a
  class name of an Authorization implementation. A good candidate may be JaasAuthorization.
  
  TODO further explanation and examples. For the moment please look at the Authorization class for more implementation details.
negative.code: }
  ----
  If the role name is specified then this role is need for all types of Transactions. For read, insert, update
  and delete. But sometimes you may want to restrict only the write access for some user. You can do this by annotate
  different roles for the different types of Transactions:
  [source,java]
  ----
  @Role(value = "ReadRole")
  