Here is more from the docs

Sorry I don't have ANY code that uses this
Class SystemLog
java.lang.Object
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+--be.xxxx.common.logging.SystemLog
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public class SystemLog
extends java.lang.Object
Utility class: provide logging. This class shields clients from changes in the logging API that is used. It can use a third party logging API, an application server's logging capabilities or perhaps just write to standard out.
This version uses the Jakarta log4j logging library.
The order of severity is as follows:
debug: information useful for programmers, will not be logged in production state
informative: useful information on what's going on
warn: an operation encountered an unexpected condition but could continue
error: an operation failed and couldn't be continued