text: from ..plugin_registry import PluginRegistry
  
  
  class RegistryTest(PluginRegistry):
      pass
  
  
  def test_plugin_registry():
      plugins = RegistryTest()
  
      assert plugins.names() == []
      assert plugins.active == ''
      assert plugins.get() is None
      assert repr(plugins) == "RegistryTest(active='', registered=[])"
  
      plugins.register('new_plugin', lambda x: x ** 2)
      assert plugins.names() == ['new_plugin']
      assert plugins.active == ''
      assert plugins.get() is None
      assert repr(plugins) == ("RegistryTest(active='', "
                               "registered=['new_plugin'])")
  
      plugins.enable('new_plugin')
      assert plugins.names() == ['new_plugin']
      assert plugins.active == 'new_plugin'
      assert plugins.get()(3) == 9
      assert repr(plugins) == ("RegistryTest(active='new_plugin', "
                               "registered=['new_plugin'])")
  