code: def run_wagtail_migration_before_core_34(apps, schema_editor):
      
      db_alias = schema_editor.connection.alias
      emit_pre_migrate_signal(verbosity=2, interactive=False, db=db_alias)
docs: Migration 34 needs migration 0040 from wagtail core
      and this Migration will run wagtail migration before
      molo core migration 34