private static RuntimeConverter createNullableRuntimeConverter(TypeInformation<?> info) {
		final RuntimeConverter valueConverter = createRuntimeConverter(info);
		return (csvMapper, container, obj) -> {
			if (obj == null) {
				return container.nullNode();
			}
			return valueConverter.convert(csvMapper, container, obj);
		};
	}
Creates a {@link CsvRowSerializationSchema} expecting the given {@link TypeInformation}.

@param typeInfo type information used to create schema.
kafka-base/kafka-base-sink/src/main/java/com/dtstack/flink/sql/sink/kafka/serialization/CsvTupleSerializationSchema.java