code: def dumps(module, cls=PVLEncoder, **kwargs):
      
      stream = io.BytesIO()
      cls(**kwargs).encode(module, stream)
      return stream.getvalue()
docs: Serialize ``module`` as a pvl module formated byte string.
  
      :param module: a ```PVLModule``` or ```dict``` like object to serialize
  
      :param cls: the encoder class used to serialize the pvl module. You may use
          the default ``PVLEncoder`` class or provided encoder formats such as the
          ```IsisCubeLabelEncoder``` and ```PDSLabelEncoder``` classes. You may
          also provided a custom sublcass of ```PVLEncoder```
  
      :param **kwargs: the keyword arguments to pass to the encoder class.
  
      :returns: a byte string encoding of the pvl module