class EventMachine::Synchrony::ConnectionPool

data is available, or request is complete)
once it is complete (assumption: fiber will yield until
yield the connection within execute method and release
pool release whenever the request is complete. Otherwise
hijack the callbacks and errbacks to fire a connection
If the requesting method begins with "a" prefix, then

Allow the pool to behave as the underlying connection

def method_missing(method, *args, &blk)
  async = (method[0,1] == "a")
  execute(async) do |conn|
    df = conn.__send__(method, *args, &blk)
    if async
      fiber = Fiber.current
      df.callback { release(fiber) }
      df.errback { release(fiber) }
    end
    df
  end
end