### Question:
TopNObject { public static Object[] top(Collection<? extends VectorInterface> vectorItems, int n) { return top(vectorItems, n, CommonConst.EMPTY_OBJECT_ARRAY); }  static Object[] top(Collection<? extends VectorInterface> vectorItems, int n); static Object[] top(Collection<? extends VectorInterface> vectorItems, int n, Object[] newObject);  }### Answer:
@Test public void testTopN() { Map<String, ? extends VectorInterface> vectorMap = getAllVectorMap(); for (int column = -1; column >= 0; column--) { ApiLogger.debug(column); } Object[] result = (Object[]) TopNObject.top(vectorMap.values(), 20); ApiLogger.debug("result length:" + result.length + ", result" + Arrays.toString(result)); result = TopNObject.top(vectorMap.values(), 30, CommonConst.EMPTY_LONG_OBJECT_ARRAY); ApiLogger.debug("result length:" + result.length + ", result" + Arrays.toString(result)); result = TopNObject.top(vectorMap.values(), CommonConst.TIMELINE_SIZE, CommonConst.EMPTY_LONG_OBJECT_ARRAY); ApiLogger.debug("result length:" + result.length + ", result" + Arrays.toString(result)); }