code: func SessionFromAssertion(assertion *saml.Assertion) *auth.Session {
  	login := assertion.Subject.NameID.Value
  	user := &empire.User{
  		Name: login,
  	}
  
  	session := auth.NewSession(user)
  	session.ExpiresAt = &assertion.AuthnStatement.SessionNotOnOrAfter
  	return session
  }
docs: // SessionFromAssertion returns a new auth.Session generated from the SAML
  // assertion.