title: Can NPOI Mapper set the row number
body: <p>I'm currently using npoi.mapper in c# to read an excel file into poco classes for further processing and it is all working very well.</p>
  
  <p>The system has grown and several spreadsheets are often processed in parrallel I would thefore like to include the filename and row number in my poco class to use for debugging purposes.</p>
  
  <p>So far I've just added the filename and row number in by hand in a for loop but was wondering if I could refactor &amp; clean up my code by having npoi.mapper do this for me?</p>
  
  <p>heres my code: </p>
  
  <pre><code>   var mapper = new Mapper(excelStream);
     var rows = mapper.Take&lt;MyPocoClass&gt;("Sheet2");
  
     for(int i = 0; i &lt; rows.Length; i++)
     {
         var row = rows[i];
  
         row.Filename = excelName;
         row.RowNumber = i;
     } 
  </code></pre>
  
  <p>I've read the documentation over on the <a href="https://github.com/donnytian/Npoi.Mapper" rel="nofollow noreferrer">GitHub Page</a> and it sounds like I should be using a custom resolver, but I cannot see how to access the row number as part of that?</p>