THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
Adding a markup filter
In some very rare cases it might be necessary to add an additional markup filter to the default list. Lets say you want to log a warning or throw an exception in case of an empty src attribute like <img src="">. The Image component is not able to handle it because the wicket id is missing. A markup filter in contrast iterates over all xml tags and is able to detect the problem and to throw an exception.
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