code: function compare(start, end, max) {
      var diff = end.line - start.line
      var lines = Math.abs(diff) - max
      var reason
  
      if (lines > 0) {
        reason =
          'Remove ' +
          lines +
          ' ' +
          plural('line', lines) +
          ' ' +
          (diff > 0 ? 'before' : 'after') +
          ' node'
  
        file.message(reason, end)
      }
    }
docs: Compare the difference between `start` and `end`, and warn when that difference exceeds `max`.