title: How to use the SumAll property?
body: <p>I have a report with a column <code>TaxBase</code> printed by a method <code>TaxBase()</code>.</p>
  
  <p>At the end of my report section I need to display the Sum of TaxBase column. 
  I don't know how!</p>
  
  <p>Maybe the property <strong>SumAll</strong> can help? But, how is it used?</p>