         let voice = "No voice"
         let synthIncorrectExpectation = expectationWithDescription("Synthesize Incorrect Voice Audio")
         
-        service!.synthesize(testString, voice: voice) {
+        service.synthesize(testString, voice: voice) {
             data, error in
             
             XCTAssertNotNil(error)

        
        let synthEmptyExpectation = expectationWithDescription("Synthesize Incorrect Voice Audio")
        
        service!.synthesize("") { data, error in
            
            XCTAssertNotNil(error)
            

    func testSynthAndPlaySSML() {
        
        let synthPlaySSMLExpectation = expectationWithDescription("Synthesize Audio")

        service.synthesize(ssmlString) { data, error in
            
            if let data = data {
                
