public boolean verify(ApplicationSpec app, List<String> errors) {
        if (verify) {
            Map<String, Integer> tableNames = new HashMap<>();
            for (RoutingTableSpec table : tables) {
                String name = table.getProtocol();

                int count = tableNames.containsKey(name) ? tableNames.get(name) : 0;
                tableNames.put(name, count + 1);
                table.verify(app, errors);
            }
            for (Map.Entry<String, Integer> entry : tableNames.entrySet()) {
                int count = entry.getValue();
                if (count > 1) {
                    errors.add("Routing table '" + entry.getKey() + "' is defined " + count + " times.");
                }
            }
        }
        return errors.isEmpty();
    }
Verifies the content of this against the given application.

@param app    The application to verify against.
@param errors The list of errors found.
@return True if no errors where found.
messagebus/src/main/java/com/yahoo/messagebus/routing/RoutingSpec.java