For a given filename, startLine, and endLine, return the corresponding code by reading it from the file. If lineToHighlight is defined, then a line containing an arrow (as a source code comment) is included right before that line.
For a given filename, startLine, and endLine, return the corresponding code by reading it from the file. If lineToHighlight is defined, then a line containing an arrow (as a source code comment) is included right before that line.