public boolean isStopped() {
    return isStopped;
  }
Returns the current state of the PeerDiscoveryAgent.

<p>If true, the node is actively listening for new connections. If false, discovery has been
turned off and the node is not listening for connections.

@return true, if the {@link PeerDiscoveryAgent} is active on this node, false, otherwise.
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/discovery/PeerDiscoveryAgent.java