pile timed fixed dimension
  for better performances. </li>
</ul>

<h4><tt>Fitter classes</tt></h4>
<ul>
  <li>Provide support for weighted likelihood unbinned fits</li>
  <li>Provide support for extended likelihood unbinned fits</li>
  <li>Provide support for not-extended binned likelihood fits (i.e. multinomial distribution instead of Poisson for bin
  contents)</li>
  <li>In case of binned likelihood fit build a Poisson or (Multinomial) likelihood ratio with the saturated model. So a
  constant term is s