{HEAD ~ The method} 11, wherein a connection is opened if the server response time is slower than the predetermined range of {TAIL ~ times} 
{ HEAD ~ The method } 11 , wherein a connection is opened if the server response time is slower than the predetermined range of { TAIL ~ times }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL