docs: def ensure_table(self, cls):
          """Required functionality."""
          exists = True
          conn = get_conn()
  
          try:
              descrip = conn.describe_table(cls.get_table_name())
              assert descrip is not None
          except ResourceNotFoundException:
              # Expected - this is what we get if there is no table
              exists = False
          except JSONResponseError:
              # Also assuming no table
              exists = False
  
          if not exists:
              table = self.table_schema_call(Table.create, cls)
              assert table is not None