class Aws::AssumeRoleWebIdentityCredentials

def refresh
  # read from token file everytime it refreshes
  @assume_role_web_identity_params[:web_identity_token] = _token_from_file(@token_file)
  resp = @client.assume_role_with_web_identity(@assume_role_web_identity_params)
  creds = resp.credentials
  @credentials = Credentials.new(
    creds.access_key_id,
    creds.secret_access_key,
    creds.session_token,
    account_id: parse_account_id(resp)
  )
  @expiration = creds.expiration
end