protected void dealRetractField(boolean change, GenericRecord record) {
		schema.getFields()
				.stream()
				.filter(field -> StringUtils.equalsIgnoreCase(field.name(), retractKey))
				.findFirst()
				.ifPresent(field -> {
					if (StringUtils.equalsIgnoreCase(updateMode, EUpdateMode.UPSERT.name())) {
						record.put(retractKey, convertFlinkType(field.schema(), change));
					}
				});
	}
Creates an Avro serialization schema for the given Avro schema string.

@param avroSchemaString Avro schema string used to serialize Flink's row to Avro's record
kafka-base/kafka-base-sink/src/main/java/com/dtstack/flink/sql/sink/kafka/serialization/AvroTuple2SerializationSchema.java