Perform batches of disk I/O operations. Performing batches of disk I/O can lead to performance improvements over performing each disk I/O operation individually. Performing batches of disk I/O concurrently can lead to an even bigger performance improvement depending on the implementation of batched I/O. The batched I/O functionality in the library is separated into an abstract interface and implementations of that abstract interface. The advantage of programming against an abstract interface is that code can be agnostic to the implementation of the interface, allowing implementations to be freely swapped out. The library provides multiple implementations of batched I/O: platform-dependent implementations using the real file system (with asynchronous I/O), and a simulated implementation for testing purposes. See the System.FS.BlockIO module for an example of how to use the library.