gistfile1.rb

Eucalyptus.configure do |config|
  config.api_key = ENV['api_key']
end

Eucalyptus::Ad.find(123)
Eucalyptus::Campaign.find(123)

module Eucalyptus
  attr_accessor :configurtion
  
  def configure
    yield(configuration)
  end
end

class Configuration
  attr_accessor :api_key
  
  def graph
    @graph ||= Koala::Graph.new(api_key)
  end
end