title: createFreezePane and setColumnWidth (xlsx package
body: <p>I want to format the 2nd sheet of an Excel file I've created wih write.xlsx()
  I get that:</p>
  <p>V&lt;- loadWorkbook(&quot;vectors VA’ and K. Year 2014.xlsx&quot;)</p>
  <blockquote>
  <p>sheets &lt;- getSheets(V)</p>
  </blockquote>
  <blockquote>
  </blockquote>
  <blockquote>
  <p>createFreezePane (sheets[(2)], 1, 2, startRow=NULL, startColumn=NULL)</p>
  </blockquote>
  <p>Error in .jcall(sheet, &quot;V&quot;, &quot;createFreezePane&quot;, as.integer(colSplit - :</p>
  <p>RcallMethod: cannot determine object class</p>
  <blockquote>
  <p>setColumnWidth(sheets[(2)], 2,400)</p>
  </blockquote>
  <p>Error in .jcall(sheet, &quot;V&quot;, &quot;createFreezePane&quot;, as.integer(ic), as.integer(colWidth * :</p>
  <p>java.lang.ClassNotFoundException</p>
  <p>What is wrong? Thank you to help me. I know nothing of jeva</p>