anchor.diff:  
   -include("unittest.hrl").
   -include("scalaris.hrl").
  -
  --include_lib("eunit/include/eunit.hrl").
   
   all() -> [
           euclidian_distance
  
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:         {timetrap, {seconds, 30}}
      ].
  
  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().
  