public static TensorType extractSparseDimensions(TensorType type) {
        TensorType.Builder builder = new TensorType.Builder(type.valueType());
        type.dimensions().stream().filter(dim -> ! dim.isIndexed()).forEach(dim -> builder.mapped(dim.name()));
        return builder.build();
    }
An update used to remove cells from a sparse tensor or dense sub-spaces from a mixed tensor.

The specification of which cells to remove contains addresses using a subset or all of the sparse dimensions of the tensor type.
This is represented as a sparse tensor where cell values are set to 1.0.
document/src/main/java/com/yahoo/document/update/TensorRemoveUpdate.java