question: protected HttpHost determineProxy ( HttpHost target , HttpRequest request , HttpContext context ) throws HttpException { ProxySelector psel = this . proxySelector ; if ( psel == null ) psel = ProxySelector . getDefault ( ) ; if ( psel == null ) return null ; URI targetURI = null ; try { targetURI = new URI ( target . toURI ( ) ) ; } catch ( URISyntaxException usx ) { throw new HttpException ( "Cannot convert host to URI: " + target , usx ) ; } List < Proxy > proxies = psel . select ( targetURI ) ; Proxy p = chooseProxy ( proxies , target , request , context ) ; HttpHost result = null ; if ( p . type ( ) == Proxy . Type . HTTP ) { if ( ! ( p . address ( ) instanceof InetSocketAddress ) ) { throw new HttpException ( "Unable to handle non-Inet proxy address: " + p . address ( ) ) ; } final InetSocketAddress isa = ( InetSocketAddress ) p . address ( ) ; result = new HttpHost ( getHost ( isa ) , isa . getPort ( ) ) ; } return result ; }
target:  Determines a proxy for the given target.