private List<EnodeURL> buildEnodes(
      final List<String> bootNodes, final EnodeDnsConfiguration enodeDnsConfiguration) {
    return bootNodes.stream()
        .filter(bootNode -> !bootNode.isEmpty())
        .map(bootNode -> EnodeURLImpl.fromString(bootNode, enodeDnsConfiguration))
        .collect(Collectors.toList());
  }
Metrics System used by Besu

@return Instance of MetricsSystem
app/src/main/java/org/hyperledger/besu/cli/BesuCommand.java