def acquire(options={})
      alive_time = options[:alive_time] || @alive_time
      max_acquire = options[:max_acquire] || 1

      @backend.acquire(alive_time, max_acquire, options)
    end
def acquire(options={})
      alive_time = options[:alive_time] || @alive_time
      max_acquire = options[:max_acquire] || 1

      @backend.acquire(alive_time, max_acquire, options)
    end
:max_acquire => nil
 :alive_time => nil