subnet_to_addr(0.0.0.0/32) = 0.0.0.0 (SUCCESS)
subnet_to_addr(1.2.0.0/16) = 1.2.0.0 (SUCCESS)
subnet_to_addr(2607:f8b0:4005:803::200e/128) = 2607:f8b0:4005:803::200e (SUCCESS)