title: Error in fit.Matrix(tcm, model) : inherits(model, "mlapiEstimation") is not TRUE
body: <p>When I ran <code>fit(tcm,model)</code> using <code>text2vec</code> in R, it reports an Error in </p>
  
  <blockquote>
    <p>fit.Matrix(tcm, model) :    inherits(model, "mlapiEstimation") is not
    TRUE</p>
  </blockquote>