usage/logback-xml/src/main/resources/logback.xml

<?xml version="1.0" encoding="UTF-8"?>
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<configuration scan="true">

  <!-- the point of this file (and this project) is to supply a logging framework which:
  
       - makes it easy for a project to get the default logging 
         (include this project, perhaps as an optional dependency (not passed to downstream projects))
         
       - makes it easy for projects to customise that logging
         (override the logback-main.xml file this includes, or any of the files that includes;
         NB those files are in brooklyn-logback-includes)
         
       - makes it easy for projects to opt-out of this type of logging
         (ensure it does not include this project as a dependency)
         
       the core problem this solves is that logback does not like it if there are multiple 
       `logback.xml` files. this restriction does not apply to files included by logback.xml.
  -->
  
  <include resource="logback-main.xml"/>

</configuration>