I'm unable to set extra http headers

[svatal]

As result of
await chromeSession.SendAsync(new SetExtraHTTPHeadersCommand { Headers = new Dictionary<string, string> { {"my_custom_header", "my_value"} } });
no extra header was sent.
Same request via nodejs works:
await Network.setExtraHTTPHeaders({ headers: { "my_custom_header": "my_value" } });