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: decoder_test.go
    path of file: ./repos/yq/pkg/yqlib
    
    the code of the file until where you have to start completion: package yqlib

import (
	"bufio"
	"bytes"
	"fmt"
	"strings"
)

type formatScenario struct {
	input          string
	indent         int
	expression     string
	expected       string
	description    string
	subdescription string
	skip
    
func mustProcessFormatScenario(s formatScenario, decoder Decoder, encoder Encoder) string {

	result, err := processFormatScenario(s, decoder, encoder)
	if err != nil {
		panic(fmt.Errorf("Bad scenario %v: %w", s.description, err))
	}
	return result

}