ColumnStore implements ColumnIterable { public int size() { return length - garbageQueue.size(); } ColumnStore(Class<T> elementType, boolean indexed);  ColumnStore(GraphStore graphStore, Class<T> elementType, boolean indexed); void addColumn(final Column column); void removeColumn(final Column column); void removeColumn(final String key); int getColumnIndex(final String key); Column getColumnByIndex(final int index); Column getColumn(final String key); boolean hasColumn(String key); @Override Iterator<Column> iterator(); @Override ColumnImpl[] toArray(); @Override List<Column> toList(); @Override void doBreak(); Set<String> getColumnKeys(); void clear(); int size(); boolean deepEquals(ColumnStore<T> obj); int deepHashCode();  }
@Test public void testEmpty() { ColumnStore<Node> store = new ColumnStore(Node.class, false); Assert.assertEquals(store.size(), 0); }