void (int fromParentId, int toParentId) { if (fromParentId == -1) return; if (fromParentId == FSRecords.NULL_FILE_ID) { throw new AssertionError("Move(" + fromParentId + " -> " + toParentId + "): can't move root to become non-root"); } vfsPeer.moveChildren(fromParentId, toParentId); }