test/framework/src/main/java/org/elasticsearch/index/mapper/MapperTestCase.java
final XContentBuilder init;
        final XContentBuilder update;
        final Consumer<FieldMapper> check;
        private UpdateCheck(CheckedConsumer<XContentBuilder, IOException> update, Consumer<FieldMapper> check) throws IOException {
            this.init = fieldMapping(MapperTestCase.this::minimalMapping);
            this.update = fieldMapping(b -> {
                minimalMapping(b);
                update.accept(b);
            });
            this.check = check;
        }
        private UpdateCheck(
            CheckedConsumer<XContentBuilder, IOException> init,
            CheckedConsumer<XContentBuilder, IOException> update,
            Consumer<FieldMapper> check
        ) throws IOException {
            this.init = fieldMapping(init);
            this.update = fieldMapping(update);
            this.check = check;
        }
    }
    private record ConflictCheck(XContentBuilder init, XContentBuilder update) {}
    public class ParameterChecker {