Checksums with FreshMarker File

Some time ago, I had the idea that a checksum calculation could be added to the FreshMarker File library. FreshMarker File is an extension for FreshMarker to support the Java types File and Path. A checksum support would allow the current checksum to be added to lists of files without any major detours. The idea is quite simple. A corresponding built-in is appended behind a file or path variable.