private DocumentUpdate createTensorAssignUpdate() {
        DocumentUpdate result = new DocumentUpdate(docType, new DocumentId(documentId));
        result.addFieldUpdate(FieldUpdate.createAssign(docType.getField(tensorField),
                              createTensorFieldValue("{{x:0}:2.0}")));
        return result;
    }
Tests applying and serializing document updates.

@author Einar M R Rosenvinge
document/src/test/java/com/yahoo/document/DocumentUpdateTestCase.java