### Question:
ColumnLabels extends Observable implements Serializable { public void setAlwaysShowLabels(boolean alwaysShowLabels) { myAlwaysShowLabels = alwaysShowLabels; setChanged(); notifyObservers(ALWAYS_SHOW_LABELS_PROP); }  ObservableList<ColumnLabel> getColumnsInLabel(); boolean isAlwaysShowLabels(); void setAlwaysShowLabels(boolean alwaysShowLabels); void copyFrom(ColumnLabels other); @Override int hashCode(); @Override boolean equals(Object obj); static final String ALWAYS_SHOW_LABELS_PROP; }### Answer:
@Test public void testUpdate() { EasyMockSupport support = new EasyMockSupport(); Observer alwaysShow = createObserver(support, ColumnLabels.ALWAYS_SHOW_LABELS_PROP); support.replayAll(); ColumnLabels options = new ColumnLabels(); options.addObserver(alwaysShow); options.setAlwaysShowLabels(true); options.deleteObserver(alwaysShow); support.verifyAll(); }