private static Thread.UncaughtExceptionHandler slf4jExceptionHandler(final Logger logger) {
    return (thread, error) -> {
      if (logger.isErrorEnabled()) {
        logger.error(String.format("Uncaught exception in thread \"%s\"", thread.getName()), error);
      }
    };
  }
Returns the first logger to be created. This is used to set the default uncaught exception

@return Logger
app/src/main/java/org/hyperledger/besu/Besu.java