         {
             dispatch_async(self.queue) {
                 
-                let fileURL = self.fileURLForKey(key: key)
-                
-                guard let filePath = fileURL.path
+                guard let filePath = self.fileURLForKey(key: key)?.path
                     else
                 {
-                    assertionFailure("no cache path found: \(fileURL)")
+                    assertionFailure("no cache path found")
                     
                     return
                 }

                let fileURL = self.fileURLForKey(key: key)
                
                guard let directoryPath = directoryURL.path,
                    let filePath = fileURL.path
                else
                {
                    assertionFailure("no cache path found: \(fileURL)")
                    
                    return
                }

                
                let fileManager = NSFileManager()
                
                guard let filePath = self.fileURLForKey(key: key)?.path
                    else
                {
                    assertionFailure("no cache path found")
                    
                    return
                }
