package client import ( "context" ) type AuthCredential struct { Payload map[string]string } func NewAuthCredential(username, password string) *AuthCredential { payload := make(map[string]string) payload["username"] = username payload["password"] = password return &AuthCredential{ Payload: payload, } } func (cred *AuthCredential) GetRequestMetadata(ctx context.Context, data ...string) (map[string]string, error) { var err error return cred.Payload, err } func (cred *AuthCredential) RequireTransportSecurity() bool { return false }