public static String unifyCollisionChars(String topic) {
        return topic.replace('.', '_');
    }
Unify topic name with a period ('.') or underscore ('_'), this is only used to check collision and will not
be used to really change topic name.

@param topic A topic to unify
@return A unified topic name
clients/src/main/java/org/apache/kafka/common/internals/Topic.java