docs: def partition(self, ref=None, **kwargs):
          """ Returns partition by ref. """
          from .exc import NotFoundError
          from six import text_type
  
          if ref:
  
              for p in self.partitions: # This is slow for large datasets, like Census years.
                  if (text_type(ref) == text_type(p.name) or text_type(ref) == text_type(p.id) or
                              text_type(ref) == text_type(p.vid)):
                      return p
  
              raise NotFoundError("Failed to find partition for ref '{}' in dataset '{}'".format(ref, self.name))
  
          elif kwargs:
              from ..identity import PartitionNameQuery
  
              pnq = PartitionNameQuery(**kwargs)
              return self._find_orm