Function block_on_local 

pub fn block_on_local<T>(
    env: &mut JNIEnv<'_>,
    context: &str,
    fut: impl Future<Output = T>,
) -> Option<T>

Block on a future that borrows local (non-’static) data, panic-safe.

Unlike block_on_jni, the future may borrow from the caller’s stack; it runs on the shared JNI runtime via Handle::block_on semantics. Must NOT be called from within an existing Tokio runtime thread (that would deadlock); in that case it falls back to a fresh single-threaded runtime.