code: def delete(self):
          
          if self.instance is None:
              raise CQLEngineException("DML Query instance attribute is None")
  
          ds = DeleteStatement(self.column_family_name, timestamp=self._timestamp, conditionals=self._conditional, if_exists=self._if_exists)
          for name, col in self.model._primary_keys.items():
              val = getattr(self.instance, name)
              if val is None and not col.partition_key:
                  continue
              ds.add_where(col, EqualsOperator(), val)
          self._execute(ds)
docs: Deletes one instance