public EntityPersister requireClassPersister(String name) throws SemanticException {
EntityPersister cp;
try {
cp = findEntityPersisterByName( name );
if ( cp == null ) {
throw new QuerySyntaxException( name + " is not mapped" );
}
}
catch ( MappingException e ) {
throw new DetailedSemanticException( e.getMessage(), e );
}