on(type, callback) {
		const topicMapping = {
			'init': `${this.protocol}/init`,
			'peer': `${this.protocol}/peer`,
			'file': `${this.protocol}/file`
		};
		
		const topic = topicMapping[type] || `${this.protocol}/${type}`;
		
		this.registerTopicHandler(topic, (data, from, respond) => {
			callback(data, (responseData) => {
				respond(responseData);
			}, this.peers.get(from));
		});
	}
Register a handler for a topic (legacy API compatibility)
@param {string} type - Message type
@param {Function} callback - Message handler