Issue has a constructor with String values for fileName, packageName, message, description. Another constructor is required (same number of parameters) that uses a TreeString for these arguments.

In a second step, IssueBuilder should be refined to store the members fileName, packageName, message, description in a TreeString as well.

Issue has a constructor with String values for fileName, packageName, message, description. The constructor has to be changed to required (same number of parameters) that uses a TreeString for these arguments.

All normalization and transformation logic that is currently part of the constructor of Issue should be moved to IssueBuilder#build. The Issue constructor then needs to be changed as described above.