base.rb

class Account
  include DataMapper::Resource
  
  # ...
  # some things
  # ...
  
  def to_json
    puts "JSON!"
  end
end

inherit.rb

class Model
  def to_json
    puts "JSON!"
  end
end


class Account < Model
  include DataMapper::Resource
  
  # ...
  # some things
  # ...
  
  def to_json
    puts "JSON!"
  end
end