Function register_local_udfs 

pub fn register_local_udfs(
    ctx: &SessionContext,
    salt: Option<&str>,
) -> Result<(), UdfError>

Register all enabled local UDFs with a DataFusion context.

The salt argument is consumed only by the crypto family’s salted-hash UDF; it is ignored when that feature is disabled.

Errors

Returns an error if UDF registration fails.