### Question:
TreeViewAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.TreeViewListener { public void showMixedCheckmarkStateChanged(org.apache.pivot.wtk.TreeView arg0) { if (showMixedCheckmarkStateChanged != null) { showMixedCheckmarkStateChanged.call(arg0); } }  CallableWithArgs<Void> getSelectModeChanged(); CallableWithArgs<Void> getCheckmarksEnabledChanged(); CallableWithArgs<Void> getDisabledCheckmarkFilterChanged(); CallableWithArgs<Void> getNodeRendererChanged(); CallableWithArgs<Void> getTreeDataChanged(); CallableWithArgs<Void> getNodeEditorChanged(); CallableWithArgs<Void> getShowMixedCheckmarkStateChanged(); CallableWithArgs<Void> getDisabledNodeFilterChanged(); void setSelectModeChanged(CallableWithArgs<Void> selectModeChanged); void setCheckmarksEnabledChanged(CallableWithArgs<Void> checkmarksEnabledChanged); void setDisabledCheckmarkFilterChanged(CallableWithArgs<Void> disabledCheckmarkFilterChanged); void setNodeRendererChanged(CallableWithArgs<Void> nodeRendererChanged); void setTreeDataChanged(CallableWithArgs<Void> treeDataChanged); void setNodeEditorChanged(CallableWithArgs<Void> nodeEditorChanged); void setShowMixedCheckmarkStateChanged(CallableWithArgs<Void> showMixedCheckmarkStateChanged); void setDisabledNodeFilterChanged(CallableWithArgs<Void> disabledNodeFilterChanged); void selectModeChanged(org.apache.pivot.wtk.TreeView arg0, org.apache.pivot.wtk.TreeView.SelectMode arg1); void checkmarksEnabledChanged(org.apache.pivot.wtk.TreeView arg0); void disabledCheckmarkFilterChanged(org.apache.pivot.wtk.TreeView arg0, org.apache.pivot.util.Filter<?> arg1); void nodeRendererChanged(org.apache.pivot.wtk.TreeView arg0, org.apache.pivot.wtk.TreeView.NodeRenderer arg1); void treeDataChanged(org.apache.pivot.wtk.TreeView arg0, org.apache.pivot.collections.List<?> arg1); void nodeEditorChanged(org.apache.pivot.wtk.TreeView arg0, org.apache.pivot.wtk.TreeView.NodeEditor arg1); void showMixedCheckmarkStateChanged(org.apache.pivot.wtk.TreeView arg0); void disabledNodeFilterChanged(org.apache.pivot.wtk.TreeView arg0, org.apache.pivot.util.Filter<?> arg1);  }### Answer:
@Test public void testShowMixedCheckmarkStateChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getShowMixedCheckmarkStateChanged()); adapter.showMixedCheckmarkStateChanged(null); assertFalse(invoked[0]); adapter.setShowMixedCheckmarkStateChanged(callable); adapter.showMixedCheckmarkStateChanged(null); assertTrue(invoked[0]); }