plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.0"?>

<!--
-->

<plugin>

   <extension point="org.eclipse.emf.ecore.generated_package">
      <!-- @generated democatalog -->
      <package
            uri="http://www.example.org/democatalog"
            class="demo.catalog.democatalog.democatalogPackage"
            genModel="model/DemoCatalog.genmodel"/>
   </extension>

   <extension point="org.eclipse.emf.ecore.generated_package">
      <!-- @generated DemoCatalog -->
      <package
            uri="http://www.example.org/democatalog"
            class="demo.catalog.democatalog.DemoCatalogPackage"
            genModel="model/DemoCatalog.genmodel"/>
   </extension>

</plugin>