Stop putting code and data into the same object. It encourages way too stateful code and lots of cross-dependencies between code components. Pass around plain-o

Stop putting code and data into the same object. It encourages way too stateful code and lots of cross-dependencies between code components. Pass around plain-old-data instead and the need for dependency injection is much less needed, just inject data instead when testing. And stop adding abstractions premptively, YAGNI.