def get_proficiency_lookup_session_for_objective_bank(self, objective_bank_id=None):
if objective_bank_id is None:<EOL><INDENT>raise NullArgument<EOL><DEDENT>raise Unimplemented()<EOL>
Gets the ``OsidSession`` associated with the proficiency lookup service for the given objective bank.

        arg:    objective_bank_id (osid.id.Id): the ``Id`` of the
                obective bank
        return: (osid.learning.ProficiencyLookupSession) - a
                ``ProficiencyLookupSession``
        raise:  NotFound - no ``ObjectiveBank`` found by the given
                ``Id``
        raise:  NullArgument - ``objective_bank_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented - ``supports_proficiency_lookup()`` or
                ``supports_visible_federation()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_proficiency_lookup()`` and
        ``supports_visible_federation()`` are ``true``*