         XCTAssertEqual(grads.0, a1)
         XCTAssertEqual(grads.1, b1)
     }
+    */
 
     func testVJPConcatenationNegativeAxis() {
         let a1 = Tensor<Float>([1,2,3,4])

            ShapedArray(shape: [2, 6], scalars: [0, 1, 2, 6, 7, 8, 3, 4, 5, 9, 10, 11]))
    }

    func testVJPConcatenation() {
        let a1 = Tensor<Float>([1,2,3,4])
        let b1 = Tensor<Float>([5,6,7,8,9,10])

        ("testWholeTensorSlicing", testWholeTensorSlicing),
        ("testAdvancedIndexing", testAdvancedIndexing),
        ("testConcatenation", testConcatenation),
        // TODO(https://bugs.swift.org/browse/TF-698): Investigate test failure.
        // ("testVJPConcatenation", testVJPConcatenation),
        ("testTranspose", testTranspose),
        ("testReshape", testReshape),
        ("testFlatten", testFlatten),
