code: function gaTrackerSnippet(options) {
  	if (typeof options === 'string') {
  		options = {id: arguments[0], domain: arguments[1]};
  	} else {
  		options = options || {};
  	}
  
  	var templateData = {};
  
  	var defultValues = {
  		id: 'XXXXX-X',
  		domain: 'auto',
  		globalName: 'ga'
  	};
  
  	Object.keys(defultValues).forEach(function(key) {
  		var prop = options[key];
  		if (prop) {
  			if (typeof prop !== 'string') {
  				throw new TypeError(prop + ' is not a string. ' + key + ' property must be a string.');
  			}
  			templateData[key] = prop;
  		} else {
  			templateData[key] = defultValues[key];
  		}
  	});
  
  	if (!isVarName(templateData.globalName)) {
  		throw new Error(templateData.globalName + ' cannot be used as a global variable name.');
  	}
  
  	if (templateData.id.indexOf('UA-') === 0) {
  		templateData.id = templateData.id.substring(3);
  	}
  
  	var space;
  	if (options.minify) {
  		space = '';
  	} else {
  		space = ' ';
  	}
  
  	var code = templateData.globalName +
               '(\'create\',' + space +
               '\'UA-' + templateData.id + '\',' + space +
               '\'' + templateData.domain + '\');' +
               (options.minify ? '' : '\n') +
               templateData.globalName +
               '(\'send\',' + space + '\'pageview\');';
  
  	if (options.singleQuotes === false) {
  		code = code.replace(/'/g, '"');
  	}
  
  	return code;
  }
docs: /*!
  ga-tracker-snippet | ISC (c) Shinnosuke Watanabe
  https://github.com/shinnn/ga-tracker-snippet