This is awful.

output.sh

[root@james modules]# cat /tmp/one /tmp/two 
three
three

virtual.pp

class one {
  file { '/tmp/one':
    content => "one\n",
  }
}

class two {
  File {
    content => "two",
  }

  file { '/tmp/two': }
}

class three {
  File <| |> {
    content => "three\n",
  }
}

include one,two,three