docs: function getLineNumber() {
    var lines = this.source
      .slice(0, this.source.indexOf(this.entry) + this.entry.length)
      .match(/\n/g)
      .slice(1);
  
    // Offset by 2 because the first line number is before a line break and the
    // last line doesn't include a line break.
    return lines.length + 2;
  }