+The idea of the MDC is to define values, which stay the same over multiple log writings.
+An MDC value set once will appear in all the subsequent logs written with the logger instance.
+
+A logger instance can be shared by several goroutines.
+Respectively, also the MDC values of the logger instance are then shared by them.
+When sharing of the MDCs is not desired, separate logger instances should be used.
+
+### Log entry format