Mac address AND boot params

I get errors if remove the methods and change it to newparam

Error: Could not set 'running' on ensure: undefined method `each' for "52:54:00:0e:c5:d1":String at 253:master/env/home/manifests/site.pp
/var/lib/puppet/lib/puppet/provider/virt/libvirt.rb:160:in `network'

Do you have any suggestions ?