code: def set_default_parser(parser):
      
      if isinstance(parser, basestring):
          parser = registry.find(parser)()
      if not isinstance(parser, BaseParser):
          parser = parser()
      global _parser
      _parser = parser
docs: Set defaulr parser instance
  
      Parameters
      ----------
      parser : instance or string
          An instance or registered name of parser class.
          The specified parser instance will be used when user did not specified
          :attr:`parser` in :func:`maidenhair.functions.load` function.
  
      See also
      --------
      :func:`maidenhair.utils.plugins.Registry.register` : Register new class