code: def view_interfaces(category=None):
      
      if category is not None:
          return sorted(_plugins_interface[category][:])
      else:
          return {k: v[:] for k, v in _plugins_interface.items()}
docs: return a view of the plugin minimal class attribute interface(s)
  
      Parameters
      ----------
      category : None or str
          if str, apply for single plugin category
  
      Examples
      --------
  
      >>> from pprint import pprint
      >>> pprint(view_interfaces())
      {'decoders': ['plugin_name', 'plugin_descript', 'dict_signature'],
       'encoders': ['plugin_name', 'plugin_descript', 'objclass'],
       'parsers': ['plugin_name', 'plugin_descript', 'file_regex', 'read_file']}