code: def restore_dbinstance_from_point_in_time(self, source_instance_id,
                                                target_instance_id,
                                                use_latest=False,
                                                restore_time=None,
                                                dbinstance_class=None,
                                                port=None,
                                                availability_zone=None):
  
          
          params = {'SourceDBInstanceIdentifier' : source_instance_id,
                    'TargetDBInstanceIdentifier' : target_instance_id}
          if use_latest:
              params['UseLatestRestorableTime'] = 'true'
          elif restore_time:
              params['RestoreTime'] = restore_time.isoformat()
          if dbinstance_class:
              params['DBInstanceClass'] = dbinstance_class
          if port:
              params['Port'] = port
          if availability_zone:
              params['AvailabilityZone'] = availability_zone
          return self.get_object('RestoreDBInstanceToPointInTime',
                                 params, DBInstance)
docs: Create a new DBInstance from a point in time.
  
          :type source_instance_id: string
          :param source_instance_id: The identifier for the source DBInstance.
  
          :type target_instance_id: string
          :param target_instance_id: The identifier of the new DBInstance.
  
          :type use_latest: bool
          :param use_latest: If True, the latest snapshot availabile will
                             be used.
  
          :type restore_time: datetime
          :param restore_time: The date and time to restore from.  Only
                               used if use_latest is False.
  
          :type instance_class: str
          :param instance_class: The compute and memory capacity of the
                                 DBInstance.  Valid values are:
                                 db.m1.small | db.m1.large | db.m1.xlarge |
                                 db.m2.2xlarge | db.m2.4xlarge
  
          :type port: int
          :param port: Port number on which database accepts connections.
                       Valid values [1115-65535].  Defaults to 3306.
  
          :type availability_zone: str
          :param availability_zone: Name of the availability zone to place
                                    DBInstance into.
  
          :rtype: :class:`boto.rds.dbinstance.DBInstance`
          :return: The newly created DBInstance