anchor.diff:          data.put(StitchRequestBody.SCHEMA, Collections.singletonMap("properties", properties));
           data.put(StitchRequestBody.MESSAGES,
                   Collections.singletonList(Collections.singletonMap("data", Collections.singletonMap("id", 2))));
  -        data.put(StitchRequestBody.KEY_NAMES, Collections.singletonList("test_key"));
  +        data.put(StitchRequestBody.KEY_NAMES, "test_key");
   
           exchange.getMessage().setBody(data);
        })
  
positive.code: from("direct:sendStitch")
       .process(exchange -> {
           exchange.getMessage().setHeader(StitchConstants.SCHEMA, StitchSchema.builder().addKeyword("field_1", "string").build());
           exchange.getMessage().setHeader(StitchConstants.KEY_NAMES, Collections.singleton("field_1"));
           exchange.getMessage().setHeader(StitchConstants.TABLE_NAME, "table_1");
  
           final StitchMessage stitchMessage = StitchMessage.builder()
  
negative.code: from("direct:sendStitch")
       .process(exchange -> {
           exchange.getMessage().setHeader(StitchConstants.SCHEMA, StitchSchema.builder().addKeyword("field_1", "string").build());
           exchange.getMessage().setHeader(StitchConstants.KEY_NAMES, "field_1");
           exchange.getMessage().setHeader(StitchConstants.TABLE_NAME, "table_1");
  
          final StitchMessage stitchMessage1 = StitchMessage.builder()
  