user/src/com/google/gwt/place/Place.gwt.xml

<?xml version="1.0" encoding="UTF-8"?>
<module type="fileset">
  <inherits name='com.google.gwt.user.User'/>

  <source path="shared"/>
  <source path="impl"/>
  <generate-with class="com.google.gwt.place.rebind.PlaceHistoryMapperGenerator">
    <when-type-assignable class="com.google.gwt.place.shared.PlaceHistoryMapper"/>
  </generate-with>
</module>