code: func (bsh *BufferedServerHeader) GetKeys() (value []string) {
  	if bsh.released {
  		value = bsh.original.GetKeys()
  	} else {
  		value = bsh.original.GetKeys()
  		for key := range bsh.headerMap {
  			found := false
  			for _,v := range value {
  				if v==key {
  					found = true
  					break
  				}
  			}
  			if !found {
  				value = append(value,key)
  			}
  		}
  	}
  	return
  }
docs: // Get all header keys