Group assignment: writing a own Java logger component in a group of four, using nothing else than Java SE libraries, Maven and Jenkins. The software must be able to substitute the logger component without recompilation, just by editing the config.xml (setting jar file path and fully qualified class name of the logger).
I asked around on Slack which group is ready for a component exchange, so that we could test the switch. I found another group and I started doing some testing.

Then I got a `java.lang.NoClassDefFoundError: org/apache/log4j/Logger`. I got in touch with my peer from the other group and asked him, if they've been using log4j. Apparently they did, so I told him that the assignment was to write a logger of one's own, not just using log4j. Then he told me: "Uh, ok, I'm going to tell the guy responsible for the logger part about that..."

X-D