THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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org.apache.wicket.util.tester.WicketTester#assertErrorMessages and org.apache.wicket.util.tester.WicketTester#assertInfoMessages now accept a list/varargs of java.io.Serializable as argument, instead of list of Strings.
This makes these methods consistent with org.apache.wicket.Component#error and other feedback message related methods.
Whatever type of message you pass to Component#error() the same message type can be asserted on.
org.apache.wicket.Component#setMetaData() value could be only a Serializable WICKET-5227
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