=======================
old way (in module):
=======================
paramp.pp:
class myclass::params {
  $myparam = 'hello'
}

init.pp:
class myclass (
  $myparam = hiera('myclass::myparam', myclass::params::myparam),
) inherits myclass::params {
*snip*
}

=======================
new way (in module):
=======================
hiera.yaml:
version: 5
data_dir: data
data_hash: yaml_data
hierarchy:
  - name: 'common'
    path: 'common.yaml'

data/common.yaml:
myclass::myparam: 'hello'

init.pp:
class myclass (
  String $myparam = lookup('myclass::myparam')
) {
*snip*
}

myparam will always cause failure or be undef here, even if i pass default_value to lookup since i cannot grab
the data from hiera module data again?