old_contents: Categories = new Mongo.Collection("communities");
  
  Category = Astro.Class({
    name: 'Category',
    collection: Categories,
    fields: {
      name: {
        type: 'string',
        validator: [
          Validators.required(null, "Type in a name for your Category."),
          Validators.unique(null, "A category with this name already exists."),
          Validators.minLength(4, "Your category name has to be at least 4 letters."),
          Validators.maxLength(100, "Your category name can't be bigger than 100 letters.")
        ]
      },
      slug: {
        type: 'string',
        validator: [
          Validators.unique(null, "A category with this name already exists.")
        ]
      },
      createdAt: {
        type: 'date',
        validator: [
          Validators.required(),
        ]
      },
      totalListings: {
        type: 'number'
      }
    },
    methods: {
      updateListingCount() {
        Meteor.call("Category.updateListingCount", this._id);
      },
  
      generateSlug: function() {
        var self = this;
        Meteor.call("Helpers.generateSlug", this.name, function(error, response) {
          self.set('slug', response);
        });
      }
    }
  });
  
new_contents: Categories = new Mongo.Collection("categories");
  
  Category = Astro.Class({
    name: 'Category',
    collection: Categories,
    fields: {
      name: {
        type: 'string',
        validator: [
          Validators.required(null, "Type in a name for your Category."),
          Validators.unique(null, "A category with this name already exists."),
          Validators.minLength(4, "Your category name has to be at least 4 letters."),
          Validators.maxLength(100, "Your category name can't be bigger than 100 letters.")
        ]
      },
      slug: {
        type: 'string',
        validator: [
          Validators.unique(null, "A category with this name already exists.")
        ]
      },
      createdAt: {
        type: 'date',
        validator: [
          Validators.required(),
        ]
      },
      totalListings: {
        type: 'number'
      }
    },
    methods: {
      updateListingCount() {
        Meteor.call("Category.updateListingCount", this._id);
      },
  
      generateSlug: function() {
        var self = this;
        Meteor.call("Helpers.generateSlug", this.name, function(error, response) {
          self.set('slug', response);
        });
      }
    }
  });
  
subject: Use proper Mongo collection name.