@Override public void putAll(Long2LongMap from) {
        for (LongLongCursor cursor = from.cursor(); cursor.advance();) {
            put(cursor.key(), cursor.value());
        }
    }
@Test
    public void testPutAll() throws Exception {
        int count = 100;
        Long2LongMap entries = new Long2LongMapHsa(count, memMgr);

        for (int i = 0; i < count; i++) {
            long key = newKey();
            long value = newValue();
            entries.put(key, value);
        }

        map.putAll(entries);
        assertEquals(count, map.size());

        for (LongLongCursor cursor = map.cursor(); cursor.advance(); ) {
            assertEquals(map.get(cursor.key()), cursor.value());
        }
    }