<extension

         point="org.eclipse.core.expressions.propertyTesters">

      <propertyTester

            class="com.ebay.tools.vjet2.internal.debug.property.LaunchPropertyTester"

            id="com.ebay.tools.vjet2.debug.property.launch"

            namespace="com.ebay.tools.vjet2.debug"

            properties="launchJS,launchHTML"

            type="org.eclipse.core.runtime.IAdaptable">

      </propertyTester>

   </extension>

Specified class should be extends PropertyTester and implement related methods.

LaunchPropertyTester extends PropertyTester {

Others services register.

IFocusService focusService =
(IFocusService) PlatformUI.getWorkbench()
.getService(IFocusService.class);
focusService.addFocusTracker(text, "textControlId");

All variables collected in ISources class, User can find related variables in this class.