### Question:
FileBrowserSheetAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.FileBrowserSheetListener { public void rootDirectoryChanged(org.apache.pivot.wtk.FileBrowserSheet arg0, java.io.File arg1) { if (rootDirectoryChanged != null) { rootDirectoryChanged.call(arg0, arg1); } }  CallableWithArgs<Void> getModeChanged(); CallableWithArgs<Void> getRootDirectoryChanged(); CallableWithArgs<Void> getSelectedFilesChanged(); CallableWithArgs<Void> getDisabledFileFilterChanged(); void setModeChanged(CallableWithArgs<Void> modeChanged); void setRootDirectoryChanged(CallableWithArgs<Void> rootDirectoryChanged); void setSelectedFilesChanged(CallableWithArgs<Void> selectedFilesChanged); void setDisabledFileFilterChanged(CallableWithArgs<Void> disabledFileFilterChanged); void modeChanged(org.apache.pivot.wtk.FileBrowserSheet arg0, org.apache.pivot.wtk.FileBrowserSheet.Mode arg1); void rootDirectoryChanged(org.apache.pivot.wtk.FileBrowserSheet arg0, java.io.File arg1); void selectedFilesChanged(org.apache.pivot.wtk.FileBrowserSheet arg0, org.apache.pivot.collections.Sequence<File> arg1); void disabledFileFilterChanged(org.apache.pivot.wtk.FileBrowserSheet arg0, org.apache.pivot.util.Filter<File> arg1);  }### Answer:
@Test public void testRootDirectoryChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getRootDirectoryChanged()); adapter.rootDirectoryChanged(null, null); assertFalse(invoked[0]); adapter.setRootDirectoryChanged(callable); adapter.rootDirectoryChanged(null, null); assertTrue(invoked[0]); }