class Google::Auth::ExternalAccount::PluggableAuthCredentials

def initialize options = {}
  base_setup options
  @audience = options[:audience]
  @credential_source = options[:credential_source] || {}
  @credential_source_executable = @credential_source[:executable]
  raise "Missing excutable source. An 'executable' must be provided" if @credential_source_executable.nil?
  @credential_source_executable_command = @credential_source_executable[:command]
  if @credential_source_executable_command.nil?
    raise "Missing command field. Executable command must be provided."
  end
  @credential_source_executable_timeout_millis = @credential_source_executable[:timeout_millis] ||
                                                 EXECUTABLE_TIMEOUT_MILLIS_DEFAULT
  if @credential_source_executable_timeout_millis < EXECUTABLE_TIMEOUT_MILLIS_LOWER_BOUND ||
     @credential_source_executable_timeout_millis > EXECUTABLE_TIMEOUT_MILLIS_UPPER_BOUND
    raise "Timeout must be between 5 and 120 seconds."
  end
  @credential_source_executable_output_file = @credential_source_executable[:output_file]
end