docs: def create_tokenizer(self, name, config=dict()):
          """Create a pipeline component from a factory.
  
          name (unicode): Factory name to look up in `Language.factories`.
          config (dict): Configuration parameters to initialise component.
          RETURNS (callable): Pipeline component.
          """
          if name not in self.factories:
              raise KeyError(Errors.E002.format(name=name))
          factory = self.factories[name]
          return factory(self, **config)