code: def _get_datastreams(self):
          
          if self._create:
              # FIXME: should we default to the datastreams defined in code?
              return {}
          else:
              # NOTE: can be accessed as a cached class property via ds_list
              r = self.api.listDatastreams(self.pid)
              dsobj = parse_xml_object(ObjectDatastreams, r.content, r.url)
              return dict([(ds.dsid, ds) for ds in dsobj.datastreams])
docs: Get all datastreams that belong to this object.
  
          Returns a dictionary; key is datastream id, value is an :class:`ObjectDatastream`
          for that datastream.
  
          :rtype: dictionary