code: def gen_uuid(apps, schema_editor):
      MyModel = apps.get_model("modelchimp", "MachineLearningModel")
      for row in MyModel.objects.all():
          row.experiment_id = generate_uid()
          row.save()
  
imports: from django.db import migrations
  from modelchimp.utils.generate_uid import generate_uid
label_desc: Use image node_id 1 for calling a global function with example usage: gen_uuid(apps, schema_editor) without return types