anchor.diff:  // probs ~ { 0.25, 0.25, 0.50 };
   inform_dist_free(dist);
   ----
  -****
  +[horizontal]
  +Header::
  +    `inform/dist.h`
  +****
  
positive.code: 
  inform_dist_free(dist);
  ----
  ****
  
  ****
  
negative.code: // dist->histogram ~ {0,0}
  inform_dist_free(dist);
  ----
  [horizontal]
  Header::
      `inform/dist.h`
  ****
  
  ****
  