Balanced - Attach a card to an account without loading the account first

example.rb

require 'balanced'

key = Balanced::ApiKey.new.save
Balanced.configure(key.secret)
Balanced::Marketplace.new.save

card = Balanced::Card.new(
  :card_number => "5105105105105100",
  :expiration_month => "12",
  :expiration_year => "2015",
).save

account = Balanced::Account.new(:email_address=> '[email protected]').save

account_with_card = Balanced::Account.new(:uri=>account.uri, :card_uri=>card.uri).save()

puts account_with_card.uri
for card in account_with_card.cards:
    puts card.uri