private void lockKeyedProperty(TitanProperty prop, StoreMutator mutator) throws StorageException { TitanKey pt = prop.getPropertyKey(); assert pt.isSimple(); if (pt.hasIndex() && pt.isUnique()) { if (prop.isNew()) { mutator.acquireIndexLock(getIndexKey(prop.getAttribute()), getKeyedIndexColumn(pt), null); } else { assert prop.isRemoved(); mutator.acquireIndexLock( getIndexKey(prop.getAttribute()), getKeyedIndexColumn(pt), getIndexValue(prop)); } } }