     private let classifierName = "swift-sdk-unit-test-cars-trucks"
     private let collectionName = "swift-sdk-unit-test-faces"
     private var classifierID: String?
-    private var collectionID: String?
     private var imageFaceID: String?
     private let timeout: TimeInterval = 10.0
     private let timeoutLong: TimeInterval = 45.0

            ("testDetectFacesByURL", testDetectFacesByURL),
            ("testDetectFacesByImage1", testDetectFacesByImage1),
            ("testDetectFacesByImage2", testDetectFacesByImage2),
            ("testGetCollections", testGetCollections),
            ("testRetrieveCollectionDetails", testRetrieveCollectionDetails),
            ("testAddDeleteImageToCollection", testAddDeleteImageToCollection),
            ("testAddDeleteImageWithMetadataToCollection", testAddDeleteImageWithMetadataToCollection),
            ("testCreateDeleteCollection", testCreateDeleteCollection),
            ("testListImagesInCollection", testListImagesInCollection),
            ("testAddDeleteMetadataToImageInCollection", testAddDeleteMetadataToImageInCollection),
            ("testAddListMetadataForImageInCollection", testAddListMetadataForImageInCollection),
            ("testSimilarImages", testSimilarImages),
            ("testSimilarImagesWithInvalidFile", testSimilarImagesWithInvalidFile),
            ("testCreateClassifierWithInvalidPositiveExamples", testCreateClassifierWithInvalidPositiveExamples),
            ("testClassifyByInvalidURL", testClassifyByInvalidURL),
            ("testDetectFacesByInvalidURL", testDetectFacesByInvalidURL),
            ("testAddZipToCollection", testAddZipToCollection)
        ]
    }
    

        waitForExpectations()
    }
    
    // MARK: - Negative Tests
    
    /** Test creating a classifier with a single image for positive examples. */
    func testCreateClassifierWithInvalidPositiveExamples() {
