Function response_header_version 

pub fn response_header_version(api_key: i16, api_version: i16) -> i16

Response header version for (api_key, api_version).

Flexible versions use header v1; non-flexible use header v0. Special case (KIP-511): ApiVersions always uses header v0 because the client doesn’t yet know the broker’s supported versions when it parses this response.