[module 'N/cache'] [function 'put' not available] This is my code:

/**
*@NApiVersion 2.x
*@NScriptType Suitelet
*/
define(['N/ui/serverWidget', 'N/cache'],
	
	function(serverWidget, cache){
		
		function onRequest(context){
		
			if (context.request.method === 'GET') {
				
				var templateSelectedValue = context.request.parameters.templateSelectedValue;

				cache.put({
					key: 'mailTemplateId',
					value: templateSelectedValue,
					ttl: 300
				});	
				
				cache.Scope = PROTECTED;
			}

		}
		
	return {
		onRequest: onRequest
	};	
	
});

The error I am getting is : TypeError: Cannot find function put in object [object Object]. What am I doing wrong?