IndexImpl implements Index<T> { @Override public Number getMinValue(Column column) { checkNonNullColumnObject(column); lock(); try { AbstractIndex index = getIndex((ColumnImpl) column); return index.getMinValue(); } finally { unlock(); } } IndexImpl(ColumnStore<T> columnStore); @Override Class<T> getIndexClass(); @Override String getIndexName(); @Override int count(Column column, Object value); int count(String key, Object value); Iterable<T> get(String key, Object value); @Override Iterable<T> get(Column column, Object value); @Override boolean isSortable(Column column); @Override Number getMinValue(Column column); @Override Number getMaxValue(Column column); Iterable<Map.Entry<Object, Set<T>>> get(Column column); @Override Collection values(Column column); @Override int countValues(Column column); @Override int countElements(Column column); Object put(String key, Object value, T element); Object put(Column column, Object value, T element); void remove(String key, Object value, T element); void remove(Column column, Object value, T element); Object set(String key, Object oldValue, Object value, T element); Object set(Column column, Object oldValue, Object value, T element); void clear();  }
@Test(expectedExceptions = UnsupportedOperationException.class) public void testMinValueNoNumber() { IndexImpl<Node> index = generateEmptyIndex(); index.getMinValue(index.columnStore.getColumn("foo")); }