Hello, For a project, I need to configure a WebSocket connection using NiFi. I also need to define a custom sub-protocol in the “Sec-WebSocket-Protocol” header. I have seen that some custom headers can be defined in the parent FF with the “header.Something” attribute. In fact, all headers are defined except for the sub-protocol. How can I achieve this without having to develop my own processor? My GenerateFlowFile has the following attributes: `header.Sec-WebSocket-Protocol = Test` and another `header.Test = Test2`. The request retrieved by Wireshark only uses header.Test. Is it normal ? Thanks. (related to https://community.cloudera.com/t5/Support-Questions/Nifi-websocket-subprotocols/m-p/311764#M224816 and https://community.cloudera.com/t5/Support-Questions/NiFi-WebSocket-Headers/m-p/361488) ... View more