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/syft/examples/create_custom_sbom
    
    the code of the file until where you have to start completion: package main

import (
	"context"
	"crypto"
	"fmt"
	"os"

	"gopkg.in/yaml.v3"

	"github.com/anchore/syft/syft"
	"github.com/anchore/syft/syft/cataloging"
	"github.com/anchore/syft/syft/cataloging/filecataloging"
	"github.com/anchore/syft/syft/cataloging/pkgcataloging"
	"github.com/anchore/syft/syft/file"
	"github.com/anchore/syft/s
    
func getSBOM(src source.Source) sbom.SBOM {
	fmt.Println("creating SBOM...")

	cfg := syft.DefaultCreateSBOMConfig().
		// run the catalogers in parallel (5 at a time concurrently max)
		WithParallelism(5).
		// bake a specific tool name and version into the SBOM
		WithTool("my-tool", "v1.0").
		// catalog all files with 3 digests
		WithFilesConfig(
			filecataloging.DefaultConfig().
				WithSelection(file.AllFilesSelection).
				WithHashers(
					crypto.MD5,
					crypto.SHA1,
					crypto.SHA256,
				),
		).
		// only use OS related catalogers that would have been used with the kind of
		// source type (container image or directory), but also add a specific python cataloger
		WithCatalogerSelection(
			pkgcataloging.NewSelectionRequest().
				WithSubSelections("os").
				WithAdditions("python-package-cataloger"),
		).
		// which relationships to include
		WithRelationshipsConfig(
			cataloging.RelationshipsConfig{
				PackageFileOwnership:                          true,
				PackageFileOwnershipOverlap:                   true,
				ExcludeBinaryPackagesWithFileOwnershipOverlap: true,
			},
		).
		// add your own cataloger to the mix
		WithCatalogers(
			pkgcataloging.NewAlwaysEnabledCatalogerReference(
				newAlpineConfigurationCataloger(),
			),
		)

	s, err := syft.CreateSBOM(context.Background(), src, cfg)
	if err != nil {
		panic(err)
	}

	return *s
}