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: main.go
    path of file: ./repos/mattermost/api/server
    
    the code of the file until where you have to start completion: package main

import (
	"bytes"
	"log"
	"os"
	"text/template"

	"go/ast"
	"go/parser"
	"go/printer"
	"go/token"

	"github.com/pb33f/libopenapi"
	v3high "github.com/pb33f/libopenapi/datamodel/high/v3"
	"golang.org/x/tools/imports"
)

// exampleText defines the template in which the corresponding ExampleClient4_* body is wrapped.
const exampleText = `
package main

import (
{{- range .Imports -}}
{{- if .}}
{{"\t"}}{{.}}
{{- else}}
{{"\t"}}{{end -}}
{{- end}}
)

func main() {
{{.Body -}}
}`

func main() {
	var exampleTmpl = template.Must(template.New("example").Parse(exampleText))

	if len(os.Args) <= 1 {
		log.Fatal("Expected filename to APIv4 spec as argument")
	}

	filename := os.Args[1]
	data, err := os.ReadFile(filename)
	if err != nil {
		log.Fatalf("failed to read %s: %s", filename, err)
	}

	// Parse the Open APIv4 Spec
	document, err := libopenapi.NewDocument(data)
	if err != nil {
		log.Fatalf("Failed to parse OpenAPI spec: %s", err)
	}


    
func applyExample(tmpl *template.Template, fileSet *token.FileSet, exampleFuncs []modelFunc, operation *v3high.Operation) {
	// Not all of GET, POST, OPTIONS, etc. are defined for each operation.
	if operation == nil {
		return
	}

	var exampleFunction modelFunc
	var found = false
	for _, e := range exampleFuncs {
		if e.FuncDecl.Name.Name == "ExampleClient4_"+operation.OperationId {
			exampleFunction = e
			found = true
			break
		}
	}
	if !found {
		return
	}

	// Find all the imports used by the function so we can re-create a minimal example.
	var fileImports []string
	for _, i := range exampleFunction.File.Imports {
		fileImports = append(fileImports, i.Path.Value)
	}

	// Render the example body using the template.
	var body bytes.Buffer
	err := printer.Fprint(&body, fileSet, exampleFunction.FuncDecl.Body.List)
	if err != nil {
		log.Fatal(err)
	}

	data := struct {
		Imports []string
		Body    string
	}{
		fileImports,
		body.String(),
	}

	// Process the resulting Go file to get the right indention, minimal set of imports, etc.
	var unformattedExample bytes.Buffer
	if err := tmpl.Execute(&unformattedExample, data); err != nil {
		log.Fatalf("failed to render template: %v", err)
	}

	ignoredFilePath := "path"
	example, err := imports.Process(ignoredFilePath, unformattedExample.Bytes(), nil)
	if err != nil {
		log.Fatal(err)
	}

	// Inject the resulting code sample
	operation.Extensions["x-codeSamples"] = []struct {
		Lang   string
		Source string
	}{
		{
			Lang:   "Go",
			Source: string(example),
		},
	}
}