docs: def delete(self):
          """
          Deletes the contents of a query
          """
          #validate where clause
          partition_key = [x for x in self.model._primary_keys.values()][0]
          if not any([c.field == partition_key.column_name for c in self._where]):
              raise QueryException("The partition key must be defined on delete queries")
  
          dq = DeleteStatement(
              self.column_family_name,
              where=self._where,
              timestamp=self._timestamp
          )
          self._execute(dq)