Видео с ютуба Nodejs Proxy Server Cannot Set Headers After They Are Sent To The Client

Troubleshooting Cannot set headers after they are sent to the client Error in Node.js Proxy Server

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client

NodeJS : "ERR_HTTP_HEADERS_SENT:Cannot set headers after they are sent to the client" while