public void Combine_EmptyWithNonEmpty()
        {
            var configBuilder1 = new AnalyzerConfigBuilder();

            var configBuilder2 = new AnalyzerConfigBuilder()
                                 .SetIsEnabled(true)
                                 .SetIssueKind(IssueKind.Error)
                                 .SetInfoImportance(Importance.High)
                                 .SetChildCanDependOnParentImplicitly(true)
                                 .AddAllowRule(new NamespaceDependencyRule("N1", "N2"), new TypeNameSet {
                "T1"
            })
                                 .AddDisallowRule(new NamespaceDependencyRule("N3", "N4"))
                                 .AddVisibleTypesByNamespace(new Namespace("N5"), new TypeNameSet {
                "T2"
            })
                                 .SetMaxIssueCount(42);

            configBuilder1.Combine(configBuilder2);

            configBuilder1.IsEnabled.Should().Be(true);
            configBuilder1.IssueKind.Should().Be(IssueKind.Error);
            configBuilder1.InfoImportance.Should().Be(Importance.High);
            configBuilder1.ChildCanDependOnParentImplicitly.Should().Be(true);
            configBuilder1.AllowRules.Should().HaveCount(1);
            configBuilder1.DisallowRules.Should().HaveCount(1);
            configBuilder1.VisibleTypesByNamespace.Should().HaveCount(1);
            configBuilder1.MaxIssueCount.Should().Be(42);
        }
        public void Combine_EmptyWithEmpty()
        {
            var configBuilder1 = new AnalyzerConfigBuilder();
            var configBuilder2 = new AnalyzerConfigBuilder();

            configBuilder1.Combine(configBuilder2);

            configBuilder1.IsEnabled.Should().BeNull();
            configBuilder1.IssueKind.Should().BeNull();
            configBuilder1.InfoImportance.Should().BeNull();
            configBuilder1.ChildCanDependOnParentImplicitly.Should().BeNull();
            configBuilder1.AllowRules.Should().HaveCount(0);
            configBuilder1.DisallowRules.Should().HaveCount(0);
            configBuilder1.VisibleTypesByNamespace.Should().HaveCount(0);
            configBuilder1.MaxIssueCount.Should().BeNull();
        }