class Mysql2::EM::Client

def query(sql, opts={})
  deferable = aquery(sql, opts)
  # if EM is not running, we just get the sql result directly
  # if we get a deferable, then let's do the deferable thing.
  return deferable unless deferable.kind_of? ::EM::DefaultDeferrable
  f = Fiber.current
  deferable.callback { |res| f.resume(res) }
  deferable.errback  { |err| f.resume(err) }
  Fiber.yield.tap do |result|
    raise result if result.is_a?(::Exception)
  end
end