parameters: (self, log=None)
docstring: A base class for config loaders.
  
          log : instance of :class:`logging.Logger` to use.
                By default logger of :meth:`traitlets.config.application.Application.instance()`
                will be used
  
          Examples
          --------
          >>> cl = ConfigLoader()
          >>> config = cl.load_config()
          >>> config
          {}
docstring_summary: A base class for config loaders.
docstring_tokens: A base class for config loaders .
function: def __init__(self, log=None):
          """A base class for config loaders.
  
          log : instance of :class:`logging.Logger` to use.
                By default logger of :meth:`traitlets.config.application.Application.instance()`
                will be used
  
          Examples
          --------
          >>> cl = ConfigLoader()
          >>> config = cl.load_config()
          >>> config
          {}
          """
          self.clear()
          if log is None:
              self.log = self._log_default()
              self.log.debug('Using default logger')
          else:
              self.log = log
function_tokens: def __init__ ( self , log = None ) : self . clear ( ) if log is None : self . log = self . _log_default ( ) self . log . debug ( 'Using default logger' ) else : self . log = log