advanced patterns with `Enumerable#group_by` in Ruby 3.1 when used with custom objects
After trying multiple solutions online, I still can't figure this out... I'm working with an scenario when trying to use `Enumerable#group_by` in Ruby 3.1 with an array of custom objects. I have a `Product` class with attributes `name` and `category`. I'm trying to group these products by their category, but the resulting hash isn't behaving as expected. Here's the code snippet I have: ```ruby class Product attr_accessor :name, :category def initialize(name, category) @name = name @category = category end end products = [ Product.new('Apple', 'Fruits'), Product.new('Banana', 'Fruits'), Product.new('Carrot', 'Vegetables') ] grouped_products = products.group_by(&:category) puts grouped_products.inspect ``` When I run this, the output is: ``` {"Fruits"=>[#<Product:0x00007fffcf0f8b80>, #<Product:0x00007fffcf0f8a30>], "Vegetables"=>[#<Product:0x00007fffcf0f89e0>]} ``` The hash seems to be grouping correctly, but when I try to access the grouped products, I get unexpected results. For example, if I try to print the names of the products in the 'Fruits' category: ```ruby grouped_products['Fruits'].each { |product| puts product.name } ``` I receive a `NoMethodError` saying `undefined method 'name' for nil:NilClass`. I’ve confirmed that the products are created correctly, and they exist in the grouped hash. I've checked my Ruby version and it is indeed 3.1.0. I’m not sure why accessing the names is causing this behavior. Are there any known issues with `group_by` in Ruby 3.1, or could it be related to how I'm accessing the elements? Any help would be greatly appreciated! My development environment is Linux. Thanks in advance! I've been using Ruby for about a year now.