public void Test_BronKerbosch()
        {
            var zipCodeList = XDocument.Load("XMLFile1.xml")
                              .Root.Element("SimpleCodeList")
                              .Elements("Row")
                              .Elements("Value")
                              .Elements("ComplexValue")
                              .Select(i => new
            {
                ZipCode      = (string)i.Element(ns3 + "zipCode"),
                LocationCode = (string)i.Element(ns3 + "locationCode"),
                CaseType     = (string)i.Element(ns3 + "caseType"),
                CaseCategory = (string)i.Element(ns3 + "caseCategory")
            })
                              .ToList();

            var categoryList = XDocument.Load("XMLFile2.xml")
                               .Root.Element("SimpleCodeList")
                               .Elements("Row")
                               .Elements("Value")
                               .Where(i => (string)i.Attribute("ColumnRef") == "code")
                               .Elements("SimpleValue")
                               .Select(i => (string)i)
                               .ToList();

            var zipCodes   = zipCodeList.Select(i => i.ZipCode).Where(i => i != null).Distinct().ToList();
            var locations  = zipCodeList.Select(i => i.LocationCode).Where(i => i != null).Distinct().ToList();
            var types      = zipCodeList.Select(i => i.CaseType).Where(i => i != null).Distinct().ToList();
            var categories = categoryList.Where(i => i != null).Distinct().ToList();

            SEquatableUndirectedEdge <string> CreateEdge(string item1, string item2)
            {
                return(Comparer <string> .Default.Compare(item1, item2) <= 0 ? new SEquatableUndirectedEdge <string>(item1, item2) : new SEquatableUndirectedEdge <string>(item2, item1));
            }

            var g = new UndirectedGraph <string, SEquatableUndirectedEdge <string> >();

            foreach (var zipCode in zipCodes)
            {
                g.AddVertex("ZIPCODE:" + zipCode);
            }

            foreach (var location in locations)
            {
                g.AddVertex("LOCATION:" + location);
            }

            foreach (var type in types)
            {
                g.AddVertex("TYPE:" + type);
            }

            foreach (var category in categories)
            {
                g.AddVertex("CATEGORY:" + category);
            }

            foreach (var items in zipCodeList.Where(i => i.CaseType != null).Distinct())
            {
                g.AddVertex("TYPE:" + items.CaseType);
            }

            foreach (var items in zipCodeList.Where(i => i.CaseCategory != null).Distinct())
            {
                g.AddVertex("CATEGORY:" + items.CaseCategory);
            }

            foreach (var zipcode in zipCodes)
            {
                foreach (var zipCode2 in zipCodes)
                {
                    if (zipcode != zipCode2)
                    {
                        g.AddVerticesAndEdge(CreateEdge("ZIPCODE:" + zipcode, "ZIPCODE:" + zipCode2));
                    }
                }
            }

            foreach (var location in locations)
            {
                foreach (var location2 in locations)
                {
                    if (location != location2)
                    {
                        g.AddVerticesAndEdge(CreateEdge("LOCATION:" + location, "LOCATION:" + location2));
                    }
                }
            }

            foreach (var type in types)
            {
                foreach (var type2 in types)
                {
                    if (type != type2)
                    {
                        g.AddVerticesAndEdge(CreateEdge("TYPE:" + type, "TYPE:" + type2));
                    }
                }
            }

            foreach (var category in categories)
            {
                foreach (var category2 in categories)
                {
                    if (category != category2)
                    {
                        g.AddVerticesAndEdge(CreateEdge("CATEGORY:" + category, "CATEGORY:" + category2));
                    }
                }
            }

            foreach (var zipCode in zipCodes)
            {
                foreach (var item in zipCodeList.Where(i => i.ZipCode == zipCode))
                {
                    if (item.LocationCode != null)
                    {
                        g.AddEdge(CreateEdge("ZIPCODE:" + zipCode, "LOCATION:" + item.LocationCode));
                    }
                    else
                    {
                        g.AddEdgeRange(types.Select(location => CreateEdge("ZIPCODE:" + zipCode, "LOCATION:" + location)));
                    }

                    if (item.CaseType != null)
                    {
                        g.AddEdge(CreateEdge("ZIPCODE:" + zipCode, "TYPE:" + item.CaseType));
                    }
                    else
                    {
                        g.AddEdgeRange(types.Select(type => CreateEdge("ZIPCODE:" + zipCode, "TYPE:" + type)));
                    }

                    if (item.CaseCategory != null)
                    {
                        g.AddEdge(CreateEdge("ZIPCODE:" + zipCode, "CATEGORY:" + item.CaseCategory));
                    }
                    else
                    {
                        g.AddEdgeRange(categories.Select(category => CreateEdge("ZIPCODE:" + zipCode, "CATEGORY:" + category)));
                    }
                }
            }

            foreach (var location in locations)
            {
                foreach (var item in zipCodeList.Where(i => i.LocationCode == location))
                {
                    if (item.ZipCode != null)
                    {
                        g.AddEdge(CreateEdge("LOCATION:" + location, "ZIPCODE:" + item.ZipCode));
                    }
                    else
                    {
                        g.AddEdgeRange(zipCodes.Select(zipCode => CreateEdge("LOCATION:" + location, "ZIPCODE:" + zipCode)));
                    }

                    if (item.CaseType != null)
                    {
                        g.AddEdge(CreateEdge("LOCATION:" + location, "TYPE:" + item.CaseType));
                    }
                    else
                    {
                        g.AddEdgeRange(types.Select(type => CreateEdge("LOCATION:" + location, "TYPE:" + type)));
                    }

                    if (item.CaseCategory != null)
                    {
                        g.AddEdge(CreateEdge("LOCATION:" + location, "CATEGORY:" + item.CaseCategory));
                    }
                    else
                    {
                        g.AddEdgeRange(categories.Select(category => CreateEdge("LOCATION:" + location, "CATEGORY:" + category)));
                    }
                }
            }

            foreach (var type in types)
            {
                foreach (var item in zipCodeList.Where(i => i.CaseType == type))
                {
                    if (item.ZipCode != null)
                    {
                        g.AddEdge(CreateEdge("TYPE:" + type, "ZIPCODE:" + item.ZipCode));
                    }
                    else
                    {
                        g.AddEdgeRange(zipCodes.Select(zipCode => CreateEdge("TYPE:" + type, "ZIPCODE:" + zipCode)));
                    }

                    if (item.LocationCode != null)
                    {
                        g.AddEdge(CreateEdge("TYPE:" + type, "LOCATION:" + item.LocationCode));
                    }
                    else
                    {
                        g.AddEdgeRange(locations.Select(location => CreateEdge("TYPE:" + type, "LOCATION:" + location)));
                    }

                    if (item.CaseCategory != null)
                    {
                        g.AddEdge(CreateEdge("TYPE:" + type, "CATEGORY:" + item.CaseCategory));
                    }
                    else
                    {
                        g.AddEdgeRange(categories.Select(category => CreateEdge("TYPE:" + type, "CATEGORY:" + category)));
                    }
                }
            }

            foreach (var category in categories)
            {
                foreach (var item in zipCodeList.Where(i => i.CaseCategory == category))
                {
                    if (item.ZipCode != null)
                    {
                        g.AddEdge(CreateEdge("CATEGORY:" + category, "ZIPCODE:" + item.ZipCode));
                    }
                    else
                    {
                        g.AddEdgeRange(zipCodes.Select(zipCode => CreateEdge("CATEGORY:" + category, "ZIPCODE:" + zipCode)));
                    }

                    if (item.LocationCode != null)
                    {
                        g.AddEdge(CreateEdge("CATEGORY:" + category, "LOCATION:" + item.LocationCode));
                    }
                    else
                    {
                        g.AddEdgeRange(locations.Select(location => CreateEdge("CATEGORY:" + category, "LOCATION:" + location)));
                    }

                    if (item.CaseType != null)
                    {
                        g.AddEdge(CreateEdge("CATEGORY:" + category, "TYPE:" + item.CaseType));
                    }
                    else
                    {
                        g.AddEdgeRange(types.Select(type => CreateEdge("CATEGORY:" + category, "TYPE:" + type)));
                    }
                }
            }

            var sw = new Stopwatch();

            sw.Start();
            //var r1 = g.BronKerbosh();
            sw.Stop();
            TestContext.WriteLine($"MaximalCliques took {sw.Elapsed}.");
            sw.Reset();

            sw.Start();
            var r2 = g.BronKerboshDegeneracy();

            sw.Stop();
            TestContext.WriteLine($"MaximalCliquesDegeneracy took {sw.Elapsed}.");
            sw.Reset();

            sw.Start();
            var r3 = g.BronKerboshPivot();

            sw.Stop();
            TestContext.WriteLine($"MaximalCliquesPivot took {sw.Elapsed}.");
            sw.Reset();

            r2 = r2.Where(i => i.Any(j => j.StartsWith("ZIPCODE")) && i.Any(j => j.StartsWith("LOCATION")) && i.Any(j => j.StartsWith("TYPE")) && i.Any(j => j.StartsWith("CATEGORY"))).ToList();
            r3 = r3.Where(i => i.Any(j => j.StartsWith("ZIPCODE")) && i.Any(j => j.StartsWith("LOCATION")) && i.Any(j => j.StartsWith("TYPE")) && i.Any(j => j.StartsWith("CATEGORY"))).ToList();

            r2.Should().HaveCount(72);
            r3.Should().HaveCount(72);
        }