def alias_objective_bank(self, objective_bank_id=None, alias_id=None):
raise Unimplemented()<EOL>
Adds an Id to an ObjectiveBank for the purpose of creating
        compatibility.
        The primary Id of the ObjectiveBank is determined by the
        provider. The new Id performs as an alias to the primary Id. If
        the alias is a pointer to another objective bank, it is
        reassigned to the given objective bank Id.
        arg:    aliasId (osid.id.Id): the alias Id
        raise:  ALREADY_EXISTS - aliasId is already assigned
        raise:  NotFound - objectiveBankId not found
        raise:  NullArgument - objectiveBankId or aliasId is null
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        compliance: mandatory - This method must be implemented.