{
SchemaManager schemaManager = loadSystem();
int ocrSize = schemaManager.getObjectClassRegistry().size();
int goidSize = schemaManager.getGlobalOidRegistry().size();
MutableObjectClass objectClass = new MutableObjectClass( "1.1.1" );
objectClass.addMustAttributeTypeOids( "cn", "ref", "2.5.4.3" );
assertFalse( schemaManager.add( objectClass ) );
assertEquals( 1, schemaManager.getErrors().size() );
assertTrue( schemaManager.getErrors().get( 0 ) instanceof LdapSchemaException );