I'm making a VFS for SQLite in Python using APSW, and specifically one that stores the database in memory: https://github.com/michalc/sqlite-memory-vfs
I want to test its locking logic, but so far, I haven't observed SQLite requesting the SQLITE_LOCK_PENDING lock type for a file. This lock is mentioned at https://www.sqlite.org/c3ref/io_methods.html among other places.
How can I make SQLite request the SQLITE_LOCK_PENDING lock type, so I can get confidence that the VFS works when this happens in the real world, outside of tests?