anchor.diff:          {timetrap, {seconds, 30}}
       ].
   
  -init_per_suite(Config) -> 
  -    unittest_helper:init_per_suite(Config),
  -    Config.
  -end_per_suite(Config) -> Config.
  +init_per_suite(Config) ->
  +    unittest_helper:init_per_suite(Config).
  +
  +end_per_suite(Config) ->
  +    _ = unittest_helper:end_per_suite(Config),
  +    ok.
   
   %% helper functions
   -spec in(X::any(), List::[any()]) -> boolean().
  
positive.code: % - XXX What should it do if elements/coordinates are duplicated?
  agglomerative_clustering(_Config) ->
      % crash when radius < 0
      ?assertError(function_clause, mathlib:aggloClustering([], -1)),
  
      % empty centroid list
      ?equals(mathlib:aggloClustering([], 0), []),
  
negative.code: 
  -include("unittest.hrl").
  -include("scalaris.hrl").
  
  all() -> [
          euclidian_distance
  