Missing default type_variety Attribute in eqpt_config.json for ROADM

[MirkoZETA]

Description of the Bug
When the type_variety attribute of a ROADM is not specified in the topology file, executing gnpy-transmission-example results in the following warning: WARNING missing type_variety attribute in eqpt_config.json[Roadm]

To Reproduce
Steps to reproduce the behavior:

1. Define a ROADM in your network topology without including the type_variety attribute, as shown below:

          ...other devices...

  {
      "uid": "roadm_source_1",
      "type": "Roadm",
      "params": {
        "target_pch_out_db": -20,
        "restrictions": {
          "preamp_variety_list": [],
          "booster_variety_list": []
        },
        "per_degree_pch_out_db": {}
      },
      "metadata": {
        "location": {
          "latitude": 0,
          "longitude": 0,
          "city": "source site",
          "region": null
      }
    }
  },

          ...other devices...

2. Run gnpy-transmission-example with this topology configuration.
3. Note: When using this topology in the GNPY online app, this warning does not occur, likely because the default value for type_variety is set.

Expected behavior
The ROADM definition in eqpt_config.json should default to a type_variety value when none is specified, similar to other devices. Currently, a warning appears, indicating that no default value is applied. I’m unsure if type_variety should always be defined explicitly for this specific device, but other devices seem to handle defaults without issue. Manually adding the type_variety field resolves this problem.

Workaround
To resolve this warning, modify eqpt_config.json to include the type_variety: "default" field as follows:

From:

  "Roadm": [
    {
      "target_pch_out_db": -20,
      "add_drop_osnr": 38,
      "pmd": 0,
      "pdl": 0,
      "restrictions": {
        "preamp_variety_list": [],
        "booster_variety_list": []
      }
    },
              ...other ROADMs (that specify type_variety)...
  ]

To:

  "Roadm": [
    {
      "type_variety": "default",
      "target_pch_out_db": -20,
      "add_drop_osnr": 38,
      "pmd": 0,
      "pdl": 0,
      "restrictions": {
        "preamp_variety_list": [],
        "booster_variety_list": []
      }
    },

              ...other ROADMs (that specify type_variety)...
  ]