old_contents: var https = require('https');
  module.exports = {
  	check: function(user_id, user_access_token, app_access_token, callback) {
  
  		if (!user_id || !user_access_token || !app_access_token) {
  				callback(false);
  		}
  
  		var options = {
  			host: 'graph.facebook.com',
  			path: '/debug_token?input_token=' +	user_access_token + '&access_token=' + app_access_token
  		};
  
  		https.get(options, function(res) {
  			var string_data = '';
  
  			res.on('data', function(chunk) {
  				string_data += chunk;
  			});
  
  			res.on('end', function() {
  				var json_data = JSON.parse(string_data);
  				if (json_data.data && json_data.data.is_valid && json_data.data.user_id == user_id) {
  					callback(true);
  				} else {
  					callback(false);
  				}
  			});
  		});
  };
  
new_contents: var https = require('https');
  
  /**
   * Validate Facebook access token
   *
   * @param  {String} user_id, user_access_token, app_access_token
   * @return {bool}
   */
  module.exports = {
  	check: function(user_id, user_access_token, app_access_token, callback) {
  
  		if (!user_id || !user_access_token || !app_access_token) {
  				callback(false);
  		}
  
  		var options = {
  			host: 'graph.facebook.com',
  			path: '/debug_token?input_token=' +	user_access_token + '&access_token=' + app_access_token
  		};
  
  		https.get(options, function(res) {
  			var string_data = '';
  
  			res.on('data', function(chunk) {
  				string_data += chunk;
  			});
  
  			res.on('end', function() {
  				var json_data = JSON.parse(string_data);
  				if (json_data.data && json_data.data.is_valid && json_data.data.user_id == user_id) {
  					callback(true);
  				} else {
  					callback(false);
  				}
  			});
  		});
  };
  
subject: Reformat index.js