code: def migration_exists(self, app, fixture_path):
          
          base_name = os.path.basename(fixture_path)
          # Loop through all migrations
          for migration_path in glob.glob(os.path.join(app.path, 'migrations', '*.py')):
              if base_name in open(migration_path).read():
                  return True
          return False
docs: Return true if it looks like a migration already exists.