dot_string = {
let result = "\n";
for(var i = 0; i < commits.length; i++){
commits[i].parents.forEach(d => result = result +
`"${d.sha}" [label = "${d.sha.substring(0,4)}"] \n`);
let sha = commits[i].sha;
let sha_short = sha.substring(0,4);
result = result + `"${sha}"`
+ ` [label = "${sha_short}"]`
+ "\n";
}
for(var i = 0; i < commits.length; i++){
let sha = commits[i].sha;
let sha_short = sha.substring(0,4);
commits[i].parents.forEach(d => result = result +
`"${d.sha}" -> "${sha}" \n`);
}
return result;
}