docs: def clean_partitions(self):
          """Delete partition records and any built partition files. """
          import shutil
          from ambry.orm import ColumnStat
  
          # FIXME. There is a problem with the cascades for ColumnStats that prevents them from
          # being  deleted with the partitions. Probably, they are seen to be owed by the columns instead.
          self.session.query(ColumnStat).filter(ColumnStat.d_vid == self.dataset.vid).delete()
  
          self.dataset.delete_partitions()
  
          for s in self.sources:
              s.state = None
  
          if self.build_partition_fs.exists:
              try:
                  shutil.rmtree(self.build_partition_fs.getsyspath('/'))
              except NoSysPathError:
                  pass