>An <code><a href="https://sandwich.R-Forge.R-project.org/reference/estfun.html" class="external-link">estfun</a></code> method is used by
  <code><a href="https://sandwich.R-Forge.R-project.org/reference/vcovCL.html" class="external-link">meatCL</a></code> to calculate the
  <code><a href="https://sandwich.R-Forge.R-project.org/reference/meat.html" class="external-link">meat</a></code> in the sandwich covariance estimator on which
  the log-likelihood adjustments in <code><a href="flite.html">flite</a></co