You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: parser.go
    path of file: ./repos/go-toml/internal/testsuite
    
    the code of the file until where you have to start completion: package testsuite

import (
	"bytes"
	"encoding/json"
	"fmt"

	"github.com/pelletier/go-toml/v2"
)

type parser struct{}

func (p parser) Decode(input string) (output string, outputIsError bool, retErr error
    
func (p parser) Decode(input string) (output string, outputIsError bool, retErr error) {
	defer func() {
		if r := recover(); r != nil {
			switch rr := r.(type) {
			case error:
				retErr = rr
			default:
				retErr = fmt.Errorf("%s", rr)
			}
		}
	}()

	var v interface{}

	if err := toml.Unmarshal([]byte(input), &v); err != nil {
		return err.Error(), true, nil
	}

	j, err := json.MarshalIndent(addTag("", v), "", "  ")
	if err != nil {
		return "", false, retErr
	}

	return string(j), false, retErr
}