                      }]
                    },
                    test_a: {
                        desc: 'matrix.y.data is empty array, expect no error.',
                        data: {
                            x: ['a', 'X2', null, 'd'],
                            y: [],
                        },
                        testList: [{
                            testType: 'convertToLayout',
                            cases: [{
                                input: ['X2', null],
                    