old_contents: import importlib
  from typing import List
  
  from django.conf import settings
  from django.core.checks import Error, register
  
  
  @register()
  def check_extensions(app_configs, **kwargs):
      """Confirm a correct import of plugins and manager."""
      errors = []
      check_manager(errors)
  
      plugins = settings.PLUGINS or []
  
      for plugin_path in plugins:
          check_single_plugin(plugin_path, errors)
  
      return errors
  
  
  def check_manager(errors: List[Error]):
      if not hasattr(settings, "EXTENSIONS_MANAGER") or not settings.EXTENSIONS_MANAGER:
          errors.append(Error("Settings should contain EXTENSIONS_MANAGER env"))
          return
      manager_path, _, manager_name = settings.EXTENSIONS_MANAGER.rpartition(".")
      try:
          manager_module = importlib.import_module(manager_path)
      except ModuleNotFoundError:
          errors.append(Error("Extension Manager path: %s doesn't exist" % manager_path))
      else:
          manager_class = getattr(manager_module, manager_name, None)
          if not manager_class:
              errors.append(
                  Error(
                      "Extension Manager %s doesn't exists in specific path %s"
                      % (manager_name, str(manager_module))
                  )
              )
  
  
  def check_single_plugin(plugin_path: str, errors: List[Error]):
      if not plugin_path:
          errors.append(Error("Wrong plugin_path %s" % plugin_path))
          return
      plugin_path, _, plugin_name = plugin_path.rpartition(".")
      try:
          plugin_module = importlib.import_module(plugin_path)
      except ModuleNotFoundError:
          errors.append(Error("Plugin with path: %s doesn't exist" % plugin_path))
      else:
          plugin_class = getattr(plugin_module, plugin_name, None)
          if not plugin_class:
              errors.append(
                  Error(
                      "Plugin %s doesn't exists in specific path %s"
                      % (plugin_name, str(plugin_module))
                  )
              )
  
new_contents: from typing import List
  
  from django.conf import settings
  from django.core.checks import Error, register
  from django.utils.module_loading import import_string
  
  
  @register()
  def check_extensions(app_configs, **kwargs):
      """Confirm a correct import of plugins and manager."""
      errors = []
      check_manager(errors)
  
      plugins = settings.PLUGINS or []
  
      for plugin_path in plugins:
          check_single_plugin(plugin_path, errors)
  
      return errors
  
  
  def check_manager(errors: List[Error]):
      if not hasattr(settings, "EXTENSIONS_MANAGER") or not settings.EXTENSIONS_MANAGER:
          errors.append(Error("Settings should contain EXTENSIONS_MANAGER env"))
          return
  
      try:
          import_string(settings.EXTENSIONS_MANAGER)
      except ImportError:
          errors.append(
              Error(
                  "Extension Manager path: %s doesn't exist" % settings.EXTENSIONS_MANAGER
              )
          )
  
  
  def check_single_plugin(plugin_path: str, errors: List[Error]):
      if not plugin_path:
          errors.append(Error("Wrong plugin_path %s" % plugin_path))
          return
      try:
          import_string(plugin_path)
      except ImportError:
          errors.append(Error("Plugin with path: %s doesn't exist" % plugin_path))
  
subject: Use django helper to validate manager and plugins paths