Static JOINSPLIT_VERIFIER 

pub static JOINSPLIT_VERIFIER: Lazy<ServiceFn<fn(Item) -> BoxFuture<'static, Result<(), BoxedError>>>>

Global batch verification context for Groth16 proofs of JoinSplit statements.

This service does not yet batch verifications, see https://github.com/ZcashFoundation/zebra/issues/3127

Note that making a Service call requires mutable access to the service, so you should call .clone() on the global handle to create a local, mutable handle.