docs: public Coin getBalanceForServer(Sha256Hash id) {
          Coin balance = Coin.ZERO;
          lock.lock();
          try {
              Set<StoredClientChannel> setChannels = mapChannels.get(id);
              for (StoredClientChannel channel : setChannels) {
                  synchronized (channel) {
                      if (channel.close != null) continue;
                      balance = balance.add(channel.valueToMe);
                  }
              }
              return balance;
          } finally {
              lock.unlock();
          }
      }