api_client_injection_example.rb

class MyAppApiClient
  attr_reader :json_client
  attr_reader :xml_client

  def initialize(api_token)
    @json_client = ApiClient.new(API_KEY, JSON.method(:parse).to_proc)
    @xml_client = ApiClient.new(API_KEY, XML.method(:parse).to_proc)
  end

  def current_account
    json_client.get('/api/current_account')
  end

  def balance
    xml_client.get('/api/current_account/balance')
  end
end