pid argument doesnt work with list of pids?

[SolitudePy]

requirements.ListRequirement(
    name="pid",
    description="Filter on specific process IDs",
    element_type=int,
    optional=True,
),

supplying --pid 1,2,3 wouldnt work for the following:

vol windows.pslist.PsList: error: argument --pid: invalid <lambda> value: '8032,7692'
vol linux.pslist.PsList: error: argument --pid: invalid <lambda> value: '1,2,3'

I also tried --pid 1 --pid 2 --pid 3 is it expected behavior?