This is the current behavior. `RuntimeError: BandMath: error before execution, while setting parameter 'out' to '/tmp/test.tif': Expected a string for 'out' parameter in BandMath, got <class 'pathlib.PosixPath'> for /tmp/test.tif)` This is an easy fix, since we added `check_input_param`, we can do the same for output. Or even better, we can replace `check_input_param` with `check_io_param`.