class Net::IMAP::ResponseTooLargeError

def initialize(msg = nil, *args,
               bytes_read:        nil,
               literal_size:      nil,
               max_response_size: nil,
               **kwargs)
  @bytes_read        = bytes_read
  @literal_size      = literal_size
  @max_response_size = max_response_size
  msg ||= [
    "Response size", response_size_msg, "exceeds max_response_size",
    max_response_size && "(#{max_response_size}B)",
  ].compact.join(" ")
  super(msg, *args, **kwargs)
end

def response_size_msg
  if bytes_read && literal_size
    "(#{bytes_read}B read + #{literal_size}B literal)"
  end
end