private static void expectTensorTypeHasNoIndexedUnboundDimensions(Field field) {
        TensorType tensorType = ((TensorDataType)field.getDataType()).getTensorType();
        if (tensorType.dimensions().stream()
                .anyMatch(dim -> dim.type().equals(TensorType.Dimension.Type.indexedUnbound))) {
            throw new IllegalArgumentException("A modify update cannot be applied to tensor types with indexed unbound dimensions. " +
                                               "Field '" + field.getName() + "' has unsupported tensor type '" + tensorType + "'");
        }
    }
Reader of a "modify" update of a tensor field.
document/src/main/java/com/yahoo/document/json/readers/TensorModifyUpdateReader.java