Fix extract_instance_and_class in a class is an s-expression
Fix extract_instance_and_class in a class is an s-expression

ngeiswei/external-tools,ngeiswei/external-tools,opencog/external-tools,opencog/external-tools,opencog/external-tools,ngeiswei/external-tools,ngeiswei/external-tools,ngeiswei/external-tools,ngeiswei/external-tools,opencog/external-tools,opencog/external-tools,opencog/external-tools,opencog/external-tools