You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: fake_authenticator.rb
    path of file: ./repos/webauthn-ruby/lib/webauthn
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

require "cbor"
require "openssl"
require "securerandom"
require "webauthn/fake_authenticator/attestation_object"
require "webauthn/fake_authenticator/authenticator_data"

module WebAuthn
  class FakeAuthenticator
    def initialize
      @credentials = {}
    end

    def make_credential(
      rp_id:,
      cl
    
    def make_credential(
      rp_id:,
      client_data_hash:,
      user_present: true,
      user_verified: false,
      backup_eligibility: false,
      backup_state: false,
      attested_credential_data: true,
      sign_count: nil,
      extensions: nil
    )
      credential_id, credential_key, credential_sign_count = new_credential
      sign_count ||= credential_sign_count

      credentials[rp_id] ||= {}
      credentials[rp_id][credential_id] = {
        credential_key: credential_key,
        sign_count: sign_count + 1
      }

      AttestationObject.new(
        client_data_hash: client_data_hash,
        rp_id_hash: hashed(rp_id),
        credential_id: credential_id,
        credential_key: credential_key,
        user_present: user_present,
        user_verified: user_verified,
        backup_eligibility: backup_eligibility,
        backup_state: backup_state,
        attested_credential_data: attested_credential_data,
        sign_count: sign_count,
        extensions: extensions
      ).serialize
    end