refactor(request.go) remove extra variable
refactor(request.go) introduce buildValue
refactor(options) change OptionToString to options.toParameters
refactor move validOptions to options.go
refactor(options) move checking nil into toParameters function
refactor add switchLeader func
refactor cleanup extra logic
refactor remove extra logic
refactor use response.Location() to get the redirection location
feat(response) introduce raw response
tests fix test cases
refactor(raw response)
refactor typo
feat add rawresponse to set func family
feat add rawWatch
refactor attach curlCh to client
feat(client.go) add closeCurl func
fix add a buffer to aviod goroutine leak
refactor unnested
refactor check error rather than resp