Feature request: add unit test for write operations with cache file handle

[dentiny]

Is your feature request related to a problem? Please describe. Current unit tests only contain read operations but not write. For write operations we expect nothing happens (including profiling, and no extra flags set, etc).

Describe the solution you'd like As with other unit tests, wrap local file system with cache file system, and perform write operation.

Describe alternatives you've considered N/A

Additional context N/A

[dentiny]

Only necessary when we do write through cache.