# File lib/u2f/fake_u2f.rb, line 16
  def initialize(app_id, options = {})
    @app_id = app_id
    @counter = options.fetch(:counter, 0)
    @key_handle_raw = options.fetch(:key_handle, SecureRandom.random_bytes(32))
    @cert_subject = options.fetch(:cert_subject, "/CN=U2FTest")
  end