### Question:
LabelContainer { synchronized public String getLabel(Integer labelID) { return labelMap.get(labelID); } protected  LabelContainer(); synchronized static LabelContainer getInstance(); synchronized void addLabel(String label); synchronized Integer getLabelID(String label); synchronized String getLabel(Integer labelID); synchronized int getSize();  }### Answer:
@Test public void testGetLabel() { String label = "R3"; LabelContainer instance = new LabelContainer(); instance.addLabel(label); Integer index = 2; String result = instance.getLabel(index); Assert.assertEquals(label, result); }