class Net::IMAP

def send_literal(str, tag = nil)
  synchronize do
    put_string("{" + str.bytesize.to_s + "}" + CRLF)
    @continued_command_tag = tag
    @continuation_request_exception = nil
    begin
      @continuation_request_arrival.wait
      e = @continuation_request_exception || @exception
      raise e if e
      put_string(str)
    ensure
      @continued_command_tag = nil
      @continuation_request_exception = nil
    end
  end
end