//go:build ignore // A simple metadata mapper for testing purposespackage main import (	"encoding/json"	"fmt"	"log"	"os") func check[T comparable](in map[string]any, key string, want T) {	value, ok := in[key]	if !ok {		fmt.Fprintf(os.Stderr, "%s key not found\n", key)		os.Exit(1)	}	if value.(T) != want {		fmt.Fprintf(os.Stderr, "%s wrong - expecting %s but got %s\n", key, want, value)		os.Exit(1)	}} func main() {	// Read the input	var in map[string]any	err := json.NewDecoder(os.Stdin).Decode(&in)	if err != nil {		log.Fatal(err)	} 	// Check the input	metadata, ok := in["Metadata"]	if !ok {		fmt.Fprintf(os.Stderr, "Metadata key not found\n")		os.Exit(1)	}	check(in, "Size", 5.0)	check(in, "SrcFs", "memory:")	check(in, "SrcFsType", "object.memoryFs")	check(in, "DstFs", "dstFs:dstFsRoot")	check(in, "DstFsType", "mockfs")	check(in, "Remote", "file.txt")	check(in, "MimeType", "text/plain; charset=utf-8")	check(in, "ModTime", "2001-02-03T04:05:06.000000007Z")	check(in, "IsDir", false)	//check(in, "ID", "Potato") 	// Map the metadata	metadataOut := map[string]string{}	var out = map[string]any{		"Metadata": metadataOut,	}	for k, v := range metadata.(map[string]any) {		switch k {		case "error":			fmt.Fprintf(os.Stderr, "Error: %s\n", v)			os.Exit(1)		case "key1":			v = "two " + v.(string)		case "key3":			continue		}		metadataOut[k] = v.(string)	}	metadataOut["key0"] = "cabbage" 	// Write the output	json.NewEncoder(os.Stdout).Encode(&out)	if err != nil {		log.Fatal(err)	}}