prot.setUpProtocol(current);
current=prot;
}
}
bottom=new ForkProtocol(fork_stack_id); // bottom
current.setDownProtocol(bottom);
bottom.setUpProtocol(current);
bottom.setDownProtocol(this);
stack.topProtocol(stack.getDownProtocol()).bottomProtocol(bottom);
fork_stacks.put(fork_stack_id, bottom);