default long observeLogs(final Consumer<LogWithMetadata> logObserver) {
    return observeBlockAdded((event -> event.getLogsWithMetadata().forEach(logObserver)));
  }
Adds an observer that will get called on for every added and removed log when a new block is
added.

<p><i>No guarantees are made about the order in which the observers are invoked.</i>

@param logObserver the observer to call
@return the observer ID that can be used to remove it later.
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/chain/Blockchain.java