public static void invokeInLocator(final SerializableRunnableIF runnable) {
    VM locator = Host.getLocator();
    if (locator != null) {
      locator.invoke(runnable);
    }
  }
Invokes a <code>SerializableCallable</code> in every VM that DUnit knows about.

@param <T> the type returned by the <code>SerializableCallable</code>
@param callable the <code>SerializableCallable</code>
@return a Map of results, where the key is the VM and the value is the result for that VM
@see VM#invoke(SerializableCallableIF)
geode-dunit/src/main/java/org/apache/geode/test/dunit/Invoke.java