anchor.diff:  double rng = inform_range(arr, 6, NULL, NULL, &err);
   // rng ~ 5.0
   ----
  +[horizontal]
  +Headers::
  +    `inform/utilities.h`,
  +    `inform/utilities/binning.h`
   ****
   
   ****
  
positive.code: ----
  int *inform_random_ints(int a, int b, size_t n);
  ----
  ****
  
  ****
  
negative.code: ----
  size_t *inform_first_partitioning(size_t size);
  ----
  [horizontal]
  Headers::
      `inform/utilities.h`,
      `inform/utilities/partitions.h`
  ****
  
  ****
  