How to create spark udf use functioncatalog?

[??????]

We are using spark.Today I see the FunctionCatalog , and I have seen the 
source of 
spark\sql\core\src\test\scala\org\apache\spark\sql\connector\DataSourceV2FunctionSuite.scala 
 and have implements the ScalarFunction.But i still not konw how 
to register it in sql