question: @ SuppressWarnings ( "unchecked" ) private void readObject ( ObjectInputStream stream ) throws IOException , ClassNotFoundException { this . id = ( Integer ) stream . readObject ( ) ; this . lhs = ( NonTerminal ) stream . readObject ( ) ; this . rhs = ( List < Symbol > ) stream . readObject ( ) ; deserializeReduceAction ( stream ) ; this . lastTerminal = ( Terminal ) stream . readObject ( ) ; this . rhsSizeWithoutEpsilon = ( Integer ) stream . readObject ( ) ; this . hashCode = ( Integer ) stream . readObject ( ) ; }
target:  readObject() de-serializes a semantic action