org.apache.http.impl.client
Classes 
AbstractAuthenticationHandler
AbstractHttpClient
AbstractResponseHandler
AIMDBackoffManager
AutoRetryHttpClient
BasicAuthCache
BasicCookieStore
BasicCredentialsProvider
BasicResponseHandler
ClientParamsStack
CloseableHttpClient
ContentEncodingHttpClient
CookieSpecRegistries
DecompressingHttpClient
DefaultBackoffStrategy
DefaultClientConnectionReuseStrategy
DefaultConnectionKeepAliveStrategy
DefaultHttpClient
DefaultHttpRequestRetryHandler
DefaultProxyAuthenticationHandler
DefaultRedirectHandler
DefaultRedirectStrategy
DefaultRequestDirector
DefaultServiceUnavailableRetryStrategy
DefaultTargetAuthenticationHandler
DefaultUserTokenHandler
EntityEnclosingRequestWrapper
FutureRequestExecutionMetrics
FutureRequestExecutionService
HttpAuthenticator
HttpClientBuilder
HttpClients
HttpRequestFutureTask
IdleConnectionEvictor
LaxRedirectStrategy
NoopUserTokenHandler
NullBackoffStrategy
ProxyAuthenticationStrategy
ProxyClient
RedirectLocations
RequestWrapper
RoutedRequest
StandardHttpRequestRetryHandler
SystemDefaultCredentialsProvider
SystemDefaultHttpClient
TargetAuthenticationStrategy
Exceptions 
TunnelRefusedException