addLineNumbers function
Add line numbers to content starting from a given line.
Implementation
String addLineNumbers(String content, {int startLine = 1}) {
final lines = content.split('\n');
final buf = StringBuffer();
for (var i = 0; i < lines.length; i++) {
buf.writeln('${startLine + i}\t${lines[i]}');
}
return buf.toString().trimRight();
}