Build a microtask-batch driver wired to a custom child runner. Most
consumers want the default singleton microtaskBatchDriver instead;
this factory exists for tests and for advanced consumers who want to
inject their own runner (e.g., a runner that wraps the child in a
tracing context).
Build a microtask-batch driver wired to a custom child runner. Most consumers want the default singleton
microtaskBatchDriverinstead; this factory exists for tests and for advanced consumers who want to inject their own runner (e.g., a runner that wraps the child in a tracing context).