examples/org.eclipse.ocl.examples.ui/plugin.xml

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

<plugin>

 <extension point="org.eclipse.core.expressions.propertyTesters">
    <propertyTester id="org.eclipse.ocl.examples.ui.propertyTester"
          class="org.eclipse.ocl.examples.ui.OCLPropertyTester"      
          namespace="org.eclipse.ocl.examples.ui"
          properties="resourceSetAvailable"
          type="java.lang.Object"/>
 </extension>

</plugin>