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: repo_commitgraph.go
    path of file: ./repos/gitea/modules/git
    
    the code of the file until where you have to start completion: // Copyright 2022 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package git

import (
	"context"
	"fmt"
)

// WriteCommitGraph write commit graph to speed up repo access
// this requires git v2.18 to be installed
func WriteCommitGraph(ctx context.Context, repoPath string) error
    
func WriteCommitGraph(ctx context.Context, repoPath string) error {
	if CheckGitVersionAtLeast("2.18") == nil {
		if _, _, err := NewCommand(ctx, "commit-graph", "write").RunStdString(&RunOpts{Dir: repoPath}); err != nil {
			return fmt.Errorf("unable to write commit-graph for '%s' : %w", repoPath, err)
		}
	}
	return nil
}