class Google::Auth::Credentials

def initialize keyfile, options = {}
  verify_keyfile_provided! keyfile
  @project_id = options["project_id"] || options["project"]
  @quota_project_id = options["quota_project_id"]
  if keyfile.is_a? Signet::OAuth2::Client
    update_from_signet keyfile
  elsif keyfile.is_a? Hash
    update_from_hash keyfile, options
  else
    update_from_filepath keyfile, options
  end
  CredentialsLoader.warn_if_cloud_sdk_credentials @client.client_id
  @project_id ||= CredentialsLoader.load_gcloud_project_id
  @client.fetch_access_token!
  @env_vars = nil
  @paths = nil
  @scope = nil
end