unregisterable domains returning invalid results

[tiamat2012]

The icann_only = True option doesn't seem to be working. A quick python test:

import psl

resp = psl.domain_suffixes('host.local', icann_only=True)
print(f"local psl response = {resp}")

output:

local psl response = Suffixes(public='local', private='host.local')

I would have expected it to return None in the public value, since that should not match anything in the PSL and is not under any ICANN domain.

Any thoughts?