code: package org.omnetpp.test.unit;
  
  import org.eclipse.core.runtime.Plugin;
  import org.osgi.framework.BundleContext;
  
  /**
   * The activator class controls the plug-in life cycle
   */
  public class Activator extends Plugin {
  
      // The plug-in ID
      public static final String PLUGIN_ID = "org.omnetpp.test.unit";
  
      // The shared instance
      private static Activator plugin;
  
      /**
       * The constructor
       */
      public Activator() {
      }
  
      /*
       * (non-Javadoc)
       * @see org.eclipse.core.runtime.Plugins#start(org.osgi.framework.BundleContext)
       */
      public void start(BundleContext context) throws Exception {
          super.start(context);
          plugin = this;
  
          System.setProperty("org.omnetpp.test.unit.running", "YES");
      }
  
      /*
       * (non-Javadoc)
       * @see org.eclipse.core.runtime.Plugin#stop(org.osgi.framework.BundleContext)
       */
      public void stop(BundleContext context) throws Exception {
          plugin = null;
          super.stop(context);
      }
  
      /**
       * Returns the shared instance
       *
       * @return the shared instance
       */
      public static Activator getDefault() {
          return plugin;
      }
  
  }
  