@Nullable
    public String defaultLogName() {
        return defaultLogName;
    }
Returns the default value of the {@link RequestLog#name()} property which is used when no name was set
via {@link RequestLogBuilder#name(String, String)}.
If {@code null}, one of the following values will be used instead:
<ul>
  <li>gRPC - A capitalized method name defined in {@code io.grpc.MethodDescriptor}
      (e.g, {@code GetItems})</li>
  <li>Thrift and annotated service - a method name (e.g, {@code getItems})</li>
  <li>{@link HttpService} - an HTTP method name</li>
</ul>
core/src/main/java/com/linecorp/armeria/server/ServiceConfig.java