old_contents: 
  from pluginmgr.config import PluginBase
  from pluginmgr_test import plugin
  
  
  @plugin.register('static0')
  class Static0(PluginBase):
      pass
  
new_contents: 
  import pluginmgr.config
  from pluginmgr_test import plugin
  
  
  class PluginBase(pluginmgr.config.PluginBase):
      def __init__(self, config, *args, **kwargs):
          super(PluginBase, self).__init__(config)
          self.args = args
          self.kwargs = kwargs
  
  
  @plugin.register('static0')
  class Static0(PluginBase):
      pass
  
subject: fix tests for ctor args/kwargs