grpc/ttnctx/context.go
func TokenFromIncomingContext(ctx context.Context) (string, error) {
	md := MetadataFromIncomingContext(ctx)
	return TokenFromMetadata(md)
}
func TokenFromIncomingContext(ctx context.Context) (string, error) {
	md := MetadataFromIncomingContext(ctx)
	return TokenFromMetadata(md)
}
// TokenFromIncomingContext gets the token from the incoming context or returns ErrNoToken