recreation_centre.rb

# recreation_centre.rb

module Swimmable
  def swim
    "Can swim here!"
  end
end

class GreenSpace
  attr_reader :name, :num_trees
  
  def initialize(name, num_trees) 
    @name = name
    @num_trees = num_trees
  end
end

class CityPark < GreenSpace; end

class RecreationCentre < CityPark
  attr_reader :philanthropist
  include Swimmable

  def initialize(name, num_trees, philanthropist)
    super(name, num_trees)
    @philanthropist = philanthropist
  end
end

class Forest < GreenSpace; end

class Lake < Forest
  include Swimmable
end

dufferin_park = CityPark.new("Dufferin Park", 2000)
wallace_emerson = RecreationCentre.new("Wallace Emerson", 2, "Joe Beef")

dufferin_park.num_trees # => 2000
wallace_emerson.num_trees # => 2
wallace_emerson.swim # => "Can swim here!""
dufferin_park.swim # NoMethodError => undefined method 'swim' for CityPark...
wallace_emerson.philanthropist # => "Joe Beef"