Do refinements apply only to instance methods?

understanding_refinements.rb

    class Traveller
      def what_are_you
        puts "I'm a Backpacker"
      end

      def self.preferred_accommodation
        puts "Hostels"
      end
    end


    module Refinements
      module Money
        module InstanceMethods
          def what_are_you
            puts "I'm a cashed-up hedonist!"
          end
        end

        module ClassMethods
          def preferred_accommodation
            puts "Expensive Hotels"
          end
        end
      end

      refine(Traveller)                 { include Money::InstanceMethods }
      refine(Traveller.singleton_class) { include Money::ClassMethods    }

    end

    def unrefined
      Traveller.new.what_are_you         # => I'm a Backpacker
      Traveller.preferred_accommodation  # => Hostels
    end


    module Context
      using Refinements

      def self.refined
        Traveller.new.what_are_you         # => I'm a cashed-up hedonist!
        Traveller.preferred_accommodation  # => Expensive Hotels
      end
    end
    
    Context.refined
    unrefined