
# @testset "Similarity depth cache" begin
#     db = DB()

#     function similarity_depth(s1::Synset, s2::Synset, max_depth=5)
#         if s1 == s2
#             return 0
#         end
#         explored = Set{Synset}([s1])
#         active_set = Vector{Synset}([s1])
#         frontier = Vector{Synset}()
#         for depth in 1:max_depth
#             for synset in active_set
#                 for related in SemanticSimilarity.similar_to(db, synset)
#                     if related == s2
#                         return depth
#                     end
#                     if !(related in explored)
#                         push!(frontier, related)
#                         push!(explored, related)
#                     end
#                 end
#             end
#             active_set, frontier = frontier, active_set
#             if isempty(active_set)
#                 break
#             end
#             empty!(frontier)
#         end
#         return nothing
#     end

#     @showprogress "Similarity depths" for groups_for_word in values(SemanticSimilarity.CACHE.similarity_groups)
#         for groups in groups_for_word
#             synset = first(first(groups))
#             for i in 1:length(groups)
#                 for element in groups[i]
#                     @test similarity_depth(synset, element) == i - 1
#                 end
#             end
#         end
#     end
# end