@Test
    public void testMixedTensorInMixedFormWithSingleSparseDimensionShortForm() {
        Tensor.Builder builder = Tensor.Builder.of(TensorType.fromSpec("tensor(x{},y[3])"));
        builder.cell().label("x", 0).label("y", 0).value(2.0);
        builder.cell().label("x", 0).label("y", 1).value(3.0);
        builder.cell().label("x", 0).label("y", 2).value(4.0);
        builder.cell().label("x", 1).label("y", 0).value(5.0);
        builder.cell().label("x", 1).label("y", 1).value(6.0);
        builder.cell().label("x", 1).label("y", 2).value(7.0);
        Tensor expected = builder.build();

        String mixedJson = """
                           {
                             "blocks":{
                               "0":[2.0,3.0,4.0],
                               "1":[5.0,6.0,7.0]
                             }
                           }
                           """;
        Tensor tensor = assertTensorField(expected,
                                          createPutWithTensor(inputJson(mixedJson), "mixed_tensor"), "mixed_tensor");
        assertTrue(tensor instanceof MixedTensor); // this matters for performance
    }
Tests parsing of various tensor values set at the root, i.e. no 'cells', 'blocks' or 'values'
document/src/test/java/com/yahoo/document/json/JsonReaderTestCase.java