NSString *url = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(CFStringRef)[self requestUrlString],
(CFStringRef)@"!$&'()*+,-./:;=?@_~%#[]",
NULL,
kCFStringEncodingUTF8));
NSString *url = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault,
(CFStringRef)[self requestUrlString],
(CFStringRef)@"!$&'()*+,-./:;=?@_~%#[]",
NULL,
kCFStringEncodingUTF8));