code: def get_network_builder(name):
      
      if callable(name):
          return name
      elif name in mapping:
          return mapping[name]
      else:
          raise ValueError('Unknown network type: {}'.format(name))
docs: If you want to register your own network outside models.py, you just need:
  
      Usage Example:
      -------------
      from baselines.common.models import register
      @register("your_network_name")
      def your_network_define(**net_kwargs):
          ...
          return network_fn