code: def collect(package='perch.migrations'):
      
      package = importlib.import_module(package)
  
      for loader, name, is_pkg in pkgutil.walk_packages(package.__path__):
          importlib.import_module(package.__name__ + '.' + name)
  
      return _migrations
docs: Import all modules inside the perch.migrations package and return the
      registered migrations