Type Error when using prototypes

I'm just getting started on Prototypes, and I'm trying to test different things on a website I'm developing. But I stumbled upon an error and I'm not sure why, because I was using that property before and it worked.

I ain't no experienced JavaScript developer, I'm still learning, but here's what I got:

var defaults = {
     local_storage_key   : "Cluster",
     plugin_navigation   : ".navigation",
     plugin_wrapper      : "content-wrapper",
     iqns_class          : ".iqn"
 }
 
 var Clusters = function(environment, options){
 
     this.options = $.extend({}, defaults, options);
 
     this.environment = environment;
 
     this.viewport = $(window);
 
     this.viewport_width = this.viewport.width();
     this.viewport_height = this.viewport.height();
 
     this.data_key = this.options.local_storage_key;
 
     this.iqns_class = this.viewport.find(this.options.iqns_class);
 
     this.iqn = this.iqns_class.parent();
 
     this.shop_initiated = false;
 
     this.plugin_navigation = this.options.plugin_navigation;
 
     this.plugin_wrapper = this.options.plugin_wrapper;
 
     this.initiate_plugin(this.plugin_navigation, {
         containerID : this.plugin_wrapper,
         first       : false,
         previous    : false,
         next        : false,
         last        : false,
         startPage   : this.get_local_storage_data(),
         perPage     : 6,
         midRange    : 15,
         startRange  : 1,
         endRange    : 1,
         keyBrowse   : false,
         scrollBrowse: false,
         pause       : 0,
         clickStop   : true,
         delay       : 50,
         direction   : "auto",
         animation   : "fadeInUp",
         links       : "title",
         fallback    : 1000,
         minHeight   : true,
         callback    : function(pages) {
             this.set_local_storage_data(pages.current);
         }
     });
 
     this.initiate_auxiliars();
 
     this.set_environment();
 
 };
 
 Clusters.prototype.set_local_storage_data = function(data_val) {
     return localStorage.setItem(this.data_key, data_val);
 };
 
 Clusters.prototype.get_local_storage_data = function() {
     return +(localStorage.getItem(this.data_key) || 1);
 };
 
 Clusters.prototype.shop_iqns_selected_class = function() {
     var self = this;
     if (this.viewport_width < 980) {
         $(this.iqns_class).each(function(index, element) {
             var element = $(element);
             $(self.iqn).on('click', function() {
                 if (element.hasClass('selected')) {
                     element.removeClass('selected');
                 } else {
                     element.addClass('selected');
                 }
             });
         });
     }
 }
 
 Clusters.prototype.initiate_plugin = function(plugin_navigation, plugin_options) {
     return $(plugin_navigation).jPages(plugin_options);
 }
 
 Clusters.prototype.initiate_auxiliars = function() {
     return this.shop_iqns_selected_class();
 }
 
 Clusters.prototype.set_environment = function() {
     if(this.environment == "Development") {
         less.env = "development";
         less.watch();
     }
 }
 
 var cluster = new Clusters("Development");
 

I'm sure there's something I'm doing wrong or misunderstood about Prototyping, because otherwise I wouldn't get any errors. I'm just asking for some opinions or some directions on what I'm doing wrong, and what I should do or shouldn't do.

This is the error I get:

Uncaught TypeError: Object #<Object> has no method 'set_local_storage_data' on line 53
 

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