Small protection to avoid adding the `NSURLProtocol` class multiple times to a given `NSURLSessionConfiguration`.
Small protection to avoid adding the `NSURLProtocol` class multiple times to a given `NSURLSessionConfiguration`.

(Apple, why didn't you declare `protocolClasses` as an `NSSet`?!)

hirohisa/OHHTTPStubs,tarbrain/OHHTTPStubs,Labradorom/OHHTTPStubs,ThomWee/OHHTTPStubs,oenius/OHHTTPStubs,sessuru/OHHTTPStubs,virajs/OHHTTPStubs,oenius/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,liufeigit/OHHTTPStubs,sessuru/OHHTTPStubs,virajs/OHHTTPStubs,kazmasaurus/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,tarbrain/OHHTTPStubs,SummerHanada/OHHTTPStubs,oenius/OHHTTPStubs,ThomWee/OHHTTPStubs,ThomWee/OHHTTPStubs,manuyavuz/OHHTTPStubs,bruceflowers/OHHTTPStubs,oenius/OHHTTPStubs,SummerHanada/OHHTTPStubs,JinlianWang/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,hirohisa/OHHTTPStubs,hirohisa/OHHTTPStubs,JinlianWang/OHHTTPStubs,ThomWee/OHHTTPStubs,SummerHanada/OHHTTPStubs,liufeigit/OHHTTPStubs,tarbrain/OHHTTPStubs,virajs/OHHTTPStubs,bruceflowers/OHHTTPStubs,virajs/OHHTTPStubs,manuyavuz/OHHTTPStubs,tarbrain/OHHTTPStubs,manuyavuz/OHHTTPStubs,SummerHanada/OHHTTPStubs,hirohisa/OHHTTPStubs,vladzz/OHHTTPStubs,MaxGabriel/OHHTTPStubs,JinlianWang/OHHTTPStubs,kazmasaurus/OHHTTPStubs,JinlianWang/OHHTTPStubs,kazmasaurus/OHHTTPStubs,sessuru/OHHTTPStubs,HyprMXMobile/OHHTTPStubs,liufeigit/OHHTTPStubs,bruceflowers/OHHTTPStubs