@Test
    public void testMatchUpdateAssign() {
        roundtripSerializeJsonAndMatch(inputJson(
                "{",
                "    'update': 'DOCUMENT_ID',",
                "     'fields': {",
                "          'string_array': {",
                "               'match': {",
                "                   'element': 3,",
                "                   'assign': 'kjeks'",
                "               }",
                "          }",
                "     }",
                "}"
        ));
    }
Tests roundtrip serialization (JSON -> DocumentUpdate -> Buffer -> DocumentUpdate -> JSON) of document updates.

@author Vegard Sjonfjell
document/src/test/java/com/yahoo/document/json/DocumentUpdateJsonSerializerTest.java