public List<GrantDTO> getForTargetExcludingGrantee(GRN target, GRN grantee) {
        return db.find(DBQuery.and(
                DBQuery.is(GrantDTO.FIELD_TARGET, target.toString()),
                DBQuery.notEquals(GrantDTO.FIELD_GRANTEE, grantee.toString())
        )).toArray();
    }
@Test
    @MongoDBFixtures("grants.json")
    public void getForTargetExcludingGrantee() {
        final GRN stream = grnRegistry.parse("grn::::stream:54e3deadbeefdeadbeef0001");
        final GRN grantee = grnRegistry.parse("grn::::user:john");

        assertThat(dbService.getForTargetExcludingGrantee(stream, grantee)).hasSize(2);
    }