// For KIP-500 / KIP-631, UnregisterBrokerRequest is an admin request to
// remove registration of a broker from the cluster.
UnregisterBrokerRequest => key 64, max version 0, flexible v0+
  // The broker ID to unregister.
  BrokerID: int32

// UnregisterBrokerResponse is a response to a UnregisterBrokerRequest.
UnregisterBrokerResponse =>
  ThrottleMillis
  // Any error code, or 0.
  ErrorCode: int16
  // The error message, if any.
  ErrorMessage: nullable-string
